Another thing to watch out for is breaking traction. When the car slides, then suddenly hooks-up again, it puts a tremendous strain on the sidewall of the tire. This can cause even the best glue joint to separate, or the foam to tear away from the glue.

I've seen many cases where a car looks decent overall, and is running fair lap times, but will sometimes break traction at the rear end, snap around the corner, then square up. That is incredibly rough on the outside rear tire, and I've seen instances of EVERY brand of tire peel/chunk under those circumstances.