Tires losing air due to poor chroming process, aka paint on rims, fake chrome paint is peeling off on inside of rims, (since gm doesn't like to rustcoat any of their parts to save a couple $) causing tires not to seal to rim, as well valve stem hole is no longer round due to flaking paint and air is escaping here as well. this could lead to tire blowouts and probably has, and was probably blamed on the tire or road hazards that weren't there. i have contacted gm and cadillac and they only think their parts should last as long as extra warranty you pay for. so 3 years. after that, all parts are ok to fail in their eyes. *tr