Pretentious thats the word I was looking for. Yeah with a Taxi driver I always sit in the back and I think they prefer it that way, I've actually had taxi drivers tell me to get out of the front seat and sit in the back. I think they are worried about robberies and I've actually been told its a law unless the back seat is full you are supposed to sit in the back at least in Chicago.

WIth uber drivers since it's normal everyday people and they aren't carrying cash I feel like you said its less formal and I feel like I'm the grey poupon guy very pretentious if I hop in the backseat.