My rear rims have developed cracks while driving resulting in quick loss of tire pressure and in some cases destroying tire. this has happened to both the left and right sides, however thus far has always been isolated to the rear (model 296 19") rims. in the 16 months i have owned this vehicle, this has happened several times including on 5/11/2012, 9/9/12, 4/12/13 and 5/23/13. each time i have purchased a new rim or had the existing rim repaired at the discretion of the dealer. in none of these cases has there been any impact or driving condition that explains the failure. *tr