The main theme will stay in your head forever. It has the same tune in Japanese and English, which is somewhat of a rarity.
The Russian version of the intro song known as New Adventures of Speed Racer is permanently etched into subconscious of a whole generation.
Germans Love David Hasselhoff: While not exactly obscure in Japan, Mach GoGoGo is mostly known there for being popular in America. The original series' ratings averaged around 13-14% in Japan, which sounds impressive at first but was more along the lines of average for an anime series in that era. In fact, even the Japanese dub of the live-action film kept the American title and names of the characters and the 1997 remake was mainly made with the intention of dubbing it overseas.
The GRX from "The Fastest Car In The World" has a top speed of 250 mph and requires drivers to take a special drug to handle the speed. 250 mph is the approximate top speed of the Bugatti Veyron which has been driven that fast without any ill effects. In fact, when it was first shown on Top Gear, the presenter who first took it to said top speed was James "Captain Slow" May.
Speed's/Go's Japanese voice actor Katsuji Mori would later play another energetic character who likes being fast, ans supports the number 5.
While it's likely more a case of exaggeration, the "Aahh!" and "Ooohh!" sounds characters sometimes make at the end of their sentences have become memes in their own right, usually when reading out something with no punctuation, such as in this video.
Subbing vs. Dubbing: Many people actually prefer the dub because, well, a lot of people grew up on it and it has its Narm Charm from being made in the 60s.
Woolseyism: The "ninjas" were changed to "Assassins" in the dub. Which is actually correct, given their role in history.
Also while it did have renames, cut scenes and so on, it was one of the very first anime imports that tried to keep the spirit of the original show as faithfully as possible.
Awesome Music: The whole soundtrack, but especially Reboot, played during the final race in which Speed restarts his car from being burned out during the race and comes from dead last to first place. The track combines and recreates old pieces of the original Speed Racer soundtrack with a more modern and high-tech feel, with a bit of chorus in the background, culminating in the perfect musical accompaniment for Speed's main Moment of Awesome.
Audience-Alienating Premise: Part of the reason why the movie didn't do too well is because it tried to keep the campy tone of the original series.
Better Than Canon: In the anime, Speed was a Boring Invincible Hero who ALWAYS WON...and yet, only because Racer X always let him. In the movie, Speed is still important (as in The Chosen Oneof Car Racing), but he's toned down a bit, and this time he's better at racing than Racer X, so his victories don't seem so cheap. Trixie taking a slightly more active role is also well-received.
Misaimed Marketing / Trailers Always Lie: The advertising blundered just enough to make a difference. It appeared to be a purely badass action movie with eye-popping inventive visuals. It turned out to have a more childish tone, in keeping with the anime. The advertising also downplayed the presence of Spritle and played up the presence of Christina Ricci.
The advertising also gave the impression that it was an In Name Only adaptation.
The Scrappy: Snake Oiler is one of the whiniest and most annoying villains to appear onscreen. Though granted, that's likely the point.
Signature Scene: The final race, where, through sheer determination, Speed races all the way to first at the speed of a jet plane, grapples two racers so that they crash into each other, and basically give the laws of physics the finger.
So Bad, It's Good: Possibly Invoked. Either way, be it design or accident, it's a damn awesome movie if you're in the right mindset.
The family watching Rex's fakeFaceHeel Turn and subsequent death. Even knowing what will probably happen as a result of knowing the cartoon, watching the family deal with this is downright heartbreaking.
Few people with a sibling can avoid Inelegant Blubbering or at the very leastManly Tears when Speed lets his foot off the gas to let his dead brother's lap record stand.
And nearer the end of the film, John Goodman's Pops is heartbreakingly sincere as he refuses to make the same mistake he did with Rex, assuring Speed that he will always love him and welcome him home no matter what.
The scene in the end where we see the truth about Racer X's identity; he truly is Rex, having faked his death and undergone plastic surgery in order to disguise his true identity in order to protect Speed and his family. Made all the more heart-wrenching by Rex's decision to not reveal the truth to his family, saying it's a mistake he will have to live with.The score during the moment only adds to the waterworks.