Fully identify with you comments. It always intrigues me that two cars, same brand, make and model with different paint jobs can respond differently to the same tuning treatment. All I can figure is minor differences in motor rpm, torque, wheel base(width) and overall balance contribute to making two similar cars different. And yes, they are no longer pristine at the end of the process, and I do tell myself I will not mess up next time - but in the end I have to remind myself they are for racing and at the end of the day/season they will be battle scared. (would just like to start the first race well tuned and pristine!!!)