Autocross/Road Course driving on 15" wheels. What's your experience?

I still can't figure out why Barracudas look just fine with smaller outer diameter tires. Anthing smaller than 26" on the rear of a Duster/Demon/Dart Sport and it looks like you stole the wheels off of a Falcon.

Parked side by side, the A-body Barracuda is mush smaller so it allows the look of a smaller tire