Hey David! Don't you mean you can't wait to SEE how it controls the car? hehe. Here's a quick video of the new controller in action. I have absolutely no complaints about how it drives. It's very smooth. I tested it yesterday with average current proportional to throttle, where the average current is the running average of the last 16 current reads. I'm using a virtual pwmDuty variable that has a range of 0-2044, which I round and map onto 0-511. The pwmDuty variable is updated each time the throttle is read, which is about 1000 times a second.
Just like dlaing originally suggested, there is no more waiting for Analog to digital conversions to finish. Instead, an interrupt just happens when an A/D conversion is finished. The chip is running at 16 MHz, and the A/D clock is now running at 500 kHz, which makes for a very smooth throttle.