Cars in fiction tend to be pretty awesome. Some just look cool and go fast. Others have weapons systems and active camouflage built into them. And then there are these cars, which can transform in order to traverse terrain meant for other vehicles. Like boats. Or planes. There are practical reasons for this to be the case, of course; after all, you wouldn't want to have to give up chasing the villains because they planned a water escape that you didn't account for. The primary reason, though, is the Rule of Cool. Because being able to drive off a pier in a sports car, transform on the way down, and hit the water in a speedboat is just plain badass.
Less drastic modifications can be expected as well for different terrain on land, like retractable tire studs for driving on ice and other slick surfaces. Any weapon systems the car is equipped with will sometimes inexplicably change in order to fit the new environment; rather than missiles, the car will have torpedos.
The Gadgeteer Genius is almost certainly the one who made all these awesome modifications. A subtrope of Cool Car and a Super-Trope for Flying Car, Hubcap Hovercraft and Amphibious Automobile. Often overlaps with Cool Boat and Cool Plane, for obvious reasons.
- Speed Racer's car can become a sub.
- At the end of Back to the Future, Doc Brown travels forward to 2015 and gets some pretty major work done on the DeLorean, including a "hover conversion" that's really more of a "flight conversion". At the end of Back to the Future Part III, he does the same thing to a locomotive.
- Chitty Chitty Bang Bang might actually be the Ur-Example of this trope. The major premise was basically "Check out this car: it can fly."
- Many James Bond examples.
- Scaramanga in The Man with the Golden Gun has a car that can fly (with an attachable wing and engine).
- Bond's Lotus Esprit in The Spy Who Loved Me converts into a submarine when he drives it off a pier and then back into a sports car again when he reaches the beach.
- In Moonraker. Bond's gondola transforms into a hovercraft, allowing him to drive it onto the streets of Venice.
- Die Another Day's Colonel Moon uses hovercrafts to cruise over the Korean demilitarized zone (which is littered with mines). Bond destroys his base, and Moon is forced to go underground and build a giant sunlight-reflecting satellite to destroy the minefield, instead. (Which had to be more expensive than simply buying more hovercrafts...)
- The Last Starfighter. Centauri's car is also a starship.
- In Blues Brothers 2000, the updated Bluesmobile could function underwater.
- Quorra's car in TRON: Legacy can operate in the rough terrain off The Grid, unlike most ground vehicles in Clu's arsenal.
- Race for the Yankee Zephyr. Barney and Gilbert need money to repair their helicopter in order to salvage the Yankee Zepher. Gilbert's daughter Sally points out that the map shows plenty of roads, so they can just drive. Barney rejects these as "paper roads, government ink". The helicopter later crashes, but some friends of Gilbert modify the helicopter cabin into a caterpillar-tracked all-terrain vehicle.
- In the Russian Super-hero film Black Lightning 2009 the protagonist discovers that the used car his father bought for him as a birthday gift can fly after accidentally triggering its flight capabilities while trapped in traffic. He soon learns With Great Power Comes Great Responsibility and becomes Moscow's first super-hero.
- The Dreamside Road: The Aesir flies from place to place, though this uses a far greater amount of the stored solar power than driving.
- The Robert A. Heinlein novel The Puppet Masters has "triphibians": cars that can drive on land, fly through the air and travel on water.
- Possible example (depending on how loosely you define "car"): The Terror in Jules Verne's Master of the World functions as an aircraft, boat, submarine and automobile.
- The Magic School Bus might be the most extreme example ever, since it can transform into just about anything, from a submarine to a spacecraft to a Drill Tank to a time machine.
- MegaTraveller Referee's Companion. At Tech Level 8 vehicle transportation includes triphibians, which can travel on land, in the water and through the air.
- Champions. Vehicles can have any form of movement super characters can, including flight, swimming, tunneling and even teleportation. They can also have the power of Shapeshifting so they have an appropriate form for the movement mode they're in.
- Game Research Group's Helltank Destroyer had Triphibious Cruisers, which could travel on land, in (and under) water and through the air.
- Car Wars has "Grasshoppers", lightweight car/helicopter hybrids. Their armour tends to be rather poor, but if someone is chasing you too closely? Well, many of them come with bombs, you see...
- The Spy Hunter games are probably one of the best examples of this. In addition to being able to transform into a Cool Boat, if the armor takes too much damage, it will be shed to reveal a motorcycle (or a jetski) underneath). In the sequel, it can optionally convert into an off-road mode, where the ground clearance is raised, wheels widened and the tires have spikes come out of then, which reduces speed but significantly improves handling when off-road.
- One of the more expensive mods you can add to your car in Streets of SimCity is a flight modification which, well, allows you to fly. Why is this useful, you ask? Dude, you can make your car frakking fly. Who needs a reason?
- Certain Cybran Nation warships in Supreme Commander can deploy legs and turn into a Spider Ship, walking out of the sea and onto land to support their ground forces when assaulting a shoreline.
- In Sonic & Sega All-Stars Racing Transformed, vehicles convert between car, aircraft and boat depending on the terrain.
- Vigilante 8 and the second game feature Power Ups that change the wheels of the vehicles into propellers (for driving on the waters) and, in the Alaska stage, skis for front wheels and bulkier wheels for the back ones.
- Crash Nitro Kart: Emperor Velo tells the kidnapped racers (either Team Bandicoot or Team Evil) that he has their vehicles modified so they can race in the tracks he has set on 4 planets. The modification seems to be the wheels, which can now turn 90 degrees and emit anti-gravity/magnetic waves so they can ride on the heavily-tilted tracks or giant tube tracks.
- Red Alert 3: Every faction has access to amphibious vehicles apart from Mobile Construction Vehicles and ore harvesters:
- The Allies have the Riptide hovercraft transport, Assault Destroyer (a warship that can move on land) and Pacifier artillery (which can move on water, but can't deploy its main armament).
- The Soviets have the Stingray (a lightning-shooting boat that can move slowly on Spider Tank legs when landed), Bullfrog transport / Anti-Air vehicle, and the Grinder (a militarized steamroller).
- The Empire specializes in amphibious vehicles, what with an amphibious transport, amphibious tank, amphibious Transforming Mecha that can go from jet to hovering mech...
- In Cursed Halo, one of the Warthog variants is a flying Warthog complete with the wheels serving as rockets in a direct reference to Back to the Future.
- The new Spark built Corbettite train from Girl Genius does not really need tracks and can make its own tunnels through rocks in order to meet up with existing underground lines. The Beast also did not require tracks, but since it was a murderous machine that wanted to eat everything instead of give passengers a ride this was less than optimal.
- The Teenage Mutant Ninja Turtles' van could become a hovercraft of some sort.
- In Double-O-duck, Launchpad McQuack is given a car that can turn into a boat or an helicopter.
- Danger Mouse has a car that can also become an airplane. In fact, it's seen up in the air more often than not.
- The Wallace & Gromit short "A Close Shave" features a motorcycle sidecar that doubles as a plane.
- Superfriends (1973/74) episode "Too Hot To Handle". The aliens have a fire truck that can convert into a rocket ship and fly.
- Batman: The Brave and the Bold: Both the Batmobile and Green Arrow's Arrowcar can transform into planes. The Batmobile can also turn into a Giant Mecha.
- Filmation's Ghostbusters: The Ghostbuggy. To see the car actually driving was a rare sight (the wheels didn't have to be animated.)
- The Gadgetmobile in Gadget and the Gadgetinis and Inspector Gadget (2015). The earliest model had a plane mode in "Inspector Gadget Saves Christmas," but only to set up a "Go-Go Gadget Plane" joke.
- M.A.S.K. featured several cars that could turn into planes, and motorcycles that could turn into flying vehicles as well. Some of the other cars could deploy different types of craft (usually either a boat or a plane), leaving behind the main vehicle as a shell, and still others could convert from street cars into tank-like battle vehicles.
- In The Transformers, several of the Autobots were modified so that they could retract their wheels and replace them with hydrofoils for long-distance water travel. In addition, Brawn could turn the front end of his car into a large drill bit for tunneling. These options were never included on the original toys, although Tracks' ability to become a flying Corvette was part of his toy. (The mail-order, toy-only Omnibots Downshift and Overdrive could also become flying cars.)
- While most of the Triple Changers had vehicle modes that were completely different from each other, Springer was unique in that his helicopter mode was basically the same as his car mode, just with the rear end folded out to the rear to form a tail, and the front bumpers shifted and extended to form wings. Springer was also the only one of the original Triple Changers who retained his Cybertronian vehicle modes.
- Speaking of Triple Changers, Astrotrain didn't strictly need tracks to ferry his fellow Decepticons about in his locomotive mode, and he could even transform into shuttle mode while in transit without disrupting his passengers... somehow (considering he had to turn upside-down to complete the transformation).
- SWAT Kats: The Radical Squadron inverts this trope with the Cyclotrons. Launched from the Turbokat, the Cyclotrons launch as smaller manned aircraft, and after a couple seconds from launch, the wings and heat shield unfurl and the Cyclotron transforms from an aircraft into a motorcycle.
- On Wacky Races, the Mean Machine, Crimson Haybaler, Convert-A-Car and Creepy Coupe can go airborne where necessary. Dick Dastardly's Mean Machine was especially versatile—in "Real Gone Ape" it's used as a submarine.
- Cool McCool's Coolmobile is another vehicle that can take flight when necessary.
- The titular boys from Phineas and Ferb built one in the episode "The Secret of Success". After being disappointed by an ATV ad that showcases it can only drive through road and mud, the boys made an all-terrain vehicle that can transform as needed to go through all terrains; cliffs, snow, ice, underwater with propellers, through the sky using wing attachments, etc. And yes, it can also drive through road and mud. As the song puts it:
It's not a submarine, it's not a plane, it's not a train
Come on, let's take a ride; we're talking all terrain