Not sure if you guys know about this or not but the 17in tires are being replaced free of charge due to the high number of walls collapsing and bubbling. If you have already replaced tires due to this problem through the dealership Lexus will refund you the amount.

I only found out b/c I had to replace two tires already due to these problems. Since this hasn't been very publicized you may need to contact the dealership yourself and request that tires be ordered for you.