Hi Ken,
If you take a look @ my photo's of the Red B8 S4 Demo car it will show you the 20" wheels, then if you select Royal Oak Audi on my photo's you will see a black B8 S4 with the 19"s equiped. You really cant tell too much of a difference between the two. Both wheel sets work quite well on the vehicle.
Regards,
Jack Spinella
STaSIS Engineering