Continuity mistake: In the scene where Eric kidnaps T-Bird and forces him to drive the hot-rod to the dock, Eric holds a large silver revolver up to T-Bird's head, then removes a black automatic from T-Bird's hand and drops it into the front floorboard. A few moments into the chase we see Eric holding the black automatic to the side of T-Bird's head, and the silver revolver is gone.
Continuity mistake: When Lee takes T-Bird in his car and the chase with the Police begins, the camera flashes to look at the chase through the eyes of the crow, the Police cars emergency lights are strobes, but when the camera reverts back to the chase scene they are the old style rotating flashers.
Revealing mistake: When Draven sends T-bird to his death in his car, the real Ford Thunderbird is replaced by a fake mockup using a flimsy one-piece fiberglass body mounted on a pair of straight axles. When it explodes, the body lifts off in one piece, warping wildly while the front axle simply falls away. No proper car components like engine, transmission, suspension and so on, are seen anywhere, though they should be.
Continuity mistake: When Eric is about to leave Gideon, he points the shotgun at him, then holds it vertically. Just after he says "your job is to tell the rest of them..." we see a shot of Gideon, and the barrel of the shotgun is visible in the top left corner, pointing at him again. Back to Eric, and the shotgun's still vertical.
Continuity mistake: After Eric spreads petrol (or something ignitable), he leaves Gideon's Pawn Shop with the shotgun full of rings. When standing outside, he shoots the shotgun into the building. First of all, I doubt that even petrol could make such a big explosion. Secondly, if you watch closely, the top of the building seems to blow up before the bottom.