My first car was a 1976 Gremlin X. It wasn't bad ass, and it WAS ugly, but it isn't the winner. I have 2 nominees. One is an AMC Pacer as was earlier nominated, but it's the wagon and with the wood paneling with a yellow paint job! Heinous!
The second is the 1970 Zaporozhets from Ukraine! Every time I see one on the road (usually broke down) it just turns my stomach. Even Ukrainians make fun of them!