I have a very hard time convincing people that I'm not going to drink since I'm driving.
I don't have a good tolerance for alcohol. (I'm exaggerating when I say I can get drunk on fruitcake, but not much.) It's just not a good idea for me to have anything alcoholic if I'm going to drive. But try to convince people of that! Yes! just one drink WILL make a difference! At least if it's me taking the just one drink!
What seems to work best is explaining that I don't want to hit anyone except Dick Cheney, and then I want a larger car than the one I have.

(Do I beg on bended knee for a ride on New Year's Eve so I can have as much champagne as I want? Hell yes!! If I'm driving on New Year's Eve, I don't want champagne.)