[Ed Wright]

Friendy, if your faster car varies too much due to air density variations, it's likely too rich. Try leaning it to see if that improves.

Everything Billy listed is correct. I seldom leave last, and I like it that way. It's not so slow it's boring to drive, aerodynamic enough that it isn't too sensitive to wind, and it doesn't care if they spray the whole track in front of me. Just needs a decent driver. :-(