I doubt this will have any effect on our cars since they have clear coat, but beware having magnets on your car if it rains and then becomes sunny again. During an autocross I put magnets all over my '91 MR2, which had just a 2-stage paint and the moisture got under the magnets. It ended up burning the paint and I could never get it to polish out.
But this is a much cleaner look at the track. I'll have to do it next spring when I take mine out for the first time
