Sentinel's use of the iconic "Needs of the many" line isn't a pointless Actor Allusion - considering what the Decepticons were planning, it shows just how Ax-Crazy he'd become.
Megatron spends most of the movie watching the battle from afar, unlike the last two films where he was constantly in the heart of the battle, and the only reason he was able to subdue Sentinel was because he took the fallen Autobot by surprise. Getting a chunk of your skull blown/torn out by two separate Primes will do that to you.
Dylan comments that collecting cars helps him relieve stress. Obviously, being under the pressure of the Decepticons can be really stressful. It also provides them all with ready disguises and a place to hide, a la Soundwave.
Laserbeak takes on Bumblebee's form to befriend the daughter of one of his human workers. One might find it odd that the girl isn't that startled by his presence, but then remember that, by this time, Earth is fully aware of the Autobots' and Decepticons' existence. With that in mind, it's possible that this girl knows about Bumblebee and the Autobots, and assumed (or was told by Laserbeak) that this small, pink visitor was just an Autobot.
As pointed out in the Transformers wiki, Sentinel's theme on the soundtrack is three minutes and sixteen seconds long, corresponding to the number 316 on his altmode.
Why is Dylan so desperate for the Decepticons to win, when it's clear the Autobots are near victory? Simple: If the Autobots win, he and his associates (well, the ones that didn't get killed yet) will be labeled as war criminals for betraying the whole human race.
Don't be silly. He'd never make it to the courthouse. Or the end of the first night in custody.
Dylan and Soundwave can be seen as Evil Counterparts to Sam and Bumblebee. With that in mind, it makes perfect sense that Bumblebee would kill Soundwave, and Sam would kill Dylan.
Soundwave as a car is not just him being an evil counterpart of Bee, but fits with him as a spy. Hes working undercover and carrying out surveillance before he reveals himself.
When the Wreckers were first revealed, a lot of fans thought they would have redneck voices. They don't; instead, they're British (Cockney to be percise). So why do they have alt-modes as NASCAR Sprint Cup Series cars? Because Daytona International Speedway is about half an hour away from Canaveral, and engineers like them would want top-notch vehicle modes.
Sentinel Prime, played by Leonard Nimoy, has an Evil Spock goatee.
It's a mystery where Optimus got his new weaponry from in the third movie. But then you remember that Jetfire brandished an axe and had a machine gun that Optimus used in the second movie. Optimus salvaged Jetfire's remains for himself to honor the late seeker. Also, by using Jetfire's weapons, he can in some way fight alongside a Prime and make a positive difference.
Sentinel Prime seeks to use humans to rebuild Cybertron. Even with six billion workers, itd be like ants building on a mansion. Then again, Sentinel or the Decepticons dont necessarily need the human race as resources, just as people to rule over; its a superiority complex.
Soundwave and Dylan display characteristics of spies: they work under cover, manipulating events in their favour. However, they lose their effectiveness once they reveal themselves, and are not much good in direct combat.
Dylan in particular displays the dark traits of espionage after the reveal: he loses most of his charm, he is constantly in fear of being killed, he doesnt see or care beyond his own survival, he treats people like tools to his own desires, and he ultimately has nothing to believe in or fight for (he loses his apartment, his only main contact who could have kept him alive, and is totally alone in his final scene).
DOTM is the only film that has the Decepticons keep humanity alive, while every other film has them gunning for genocide. Its within reason to believe that Dylan was the one who suggested humanity as slaves, as a compromise to keep Earth spinning and to keep humanity intact. This makes his actions in the film more tragic and desperate, if not less evil.
With this in mind, consider that Dylans last words are him raving at Sam whether he thinks hes a hero by what he did. While Sanity Slippage is in effect at this point, from Dylans perspective by leading the humans as a slave force hes keeping them alive while Sams resistance to the Decepticons is going to get everyone killed, so in his view Sam is the one endangering them all. Hed have a point if it the Chicago massacre hadnt proven that the Decepticons are fine with killing people regardless of how useful they can be.
This TV commercial for the movie, initally sounds like just generic advertising for this big blockbuster action movie, but the brilliance comes in when you realize that "An enemy we never expected" was Foreshadowing for Sentinel Prime, Optimus' mentor's betrayal.
In the game it is mentioned that Transformers are more durable in Stealth Force mode. This makes sense if you consider how the transformers function, particularly in the films, in most cases the vehicle kibble forms armour covering a robotic frame. it makes sense therefore that Stealth Force mode would be more durable, as the armour is more complete, making it less likely that vulnerable systems could be accessible to attackers.
Dylan's entire life, when you think about it. Ever since he was young, he was told by his father about how he would eventually have to aid the Decepticons in enslaving humanity. He spent all his life knowing that, one day, a massive Alien Invasion would happen, and he would help the aliens win. Judging from his talk with Sam, it seems that, at one point, he himself questioned how one can pull off such a horrifying act on their own homeworld—- By which his father simply told him "When it's not your war, you choose the side that's going to win." He was conditioned to accept that there was no way the Decepticons would lose; after all, he knew about their plans for years, whereas the Autobots didn't arrive until between 2005-2008. By then, he was a grown man set in his ways, his father having trained him to be the way he is. It's no surprise, then, that he panicked when the Autobots gained the upper hand, because he couldn't imagine what he'd do if the 'Cons lost, not after all the years he spent overseeing their plans unfold, as well as helping them in said plans. As he tells Sam in their final confrontation, "There's only one future for me!"
The third film has the Autobots destroy an illegal nuclear plant in the Middle East. A news report later says that no country has taken responsibility for the attacks. The problem, however, is that the soldiers in the plant clearly saw Dino transform into his robot mode, and the US is the only country that has Autobots. Wouldn't people be able to put two and two together, especially since Autobots and Decepticons are now common knowledge throughout the world?
Maybe they thought Dino was Italian...
"Taken responsibility" means no country has admitted publicly that they were behind it. Bee could've gone in waving the American flag and blaring a medley of John Philip Sousa if he wanted, and technically the US, as a country, could have still not "taken responsibility" for the attack.