I did some testing, and at first my favorite car was the M3 GT2, then I realized it wasn't eligible

Then I jumped into the Viper and was instantly like 4 second faster than anything else. Then I realized it had the restrictor removed

All the cars I tested were pretty equal. The Audi was the easiest to drive fast, but lap times were mediocre. The Vette was fast in a straight line and could take the kink flat, but surprisingly didn't put up great lap times. The Viper was a nice balance of speed, handling and drive-ability. The Bentley was definitely the fastest for me, but difficult to drive. Still need to test the Lambo and Z4. Am I forgetting anything?