Continuity mistake: After the Bandit jumps the bridge Sheriff Justice rear-ends the cop car in front of him, smashing the hood of his car. In the next scene Sheriff Justice's hood is fine.
Revealing mistake: Mel jumps over a step that he senses to be weak. The step he actually jumps onto (and collapses) has been pre-cut in a zig-zag pattern. (01:26:50)
Other mistake: In the end credits, Christopher Walken's name is listed as 'Christopher Wlaken'.