Revealing mistake: When Oscar and Felix are driving on the highway, you can see the passing cars waving to the camera.
Revealing mistake: When the guy is dead in the car you can see his eyes blinking while he dead (you have to look really hard).
Oscar Madison: It took us 2 hours to get here. It's gonna take us 5 hours to go back because I don't know how the hell we got here in the first place. Then we'd have to make three stops: one for you to pee, one for you to let locked in the john, one to pay a kid $5 to get out, and then we'd have to stop again for you to eat. Do you understand what I'm talking about?