What's to wonder? 5 bolts are stronger than 4. The car is heavier, it has more power, it needs bigger brakes, bigger bearings, more bolts, etc... -PL >It also makes one wonder why "plain" Audis from the 80s had 4-bolt >wheels, while more powerful models had 5-bolts? Peter Lines CAE Systems Administrator, WARN Industries p: 503.659-8750 x4116 c: 503.319-3739 f: 503.786.4463