Hilarious in Hindsight: The rejected "Captain Kill" wardrobe design from Nygma's blueprints is a dead-ringer for Colonel Stars and Stripes, Carrey's character in Kick-Ass 2. (This works on multiple levels, as Carrey disowned both.)
Two-Face: *shoves driver out of the way* We'll drive, thank you!
Joker: *pushes lifeless mook out of the way* Excuse me! I wanna drive!
- Even better, Two-Face's Motive Rant in the beginning, about why the flip of a coin is the only kind of justice, is similar to what the Joker would feed Harvey in The Dark Knight.