QUOTE (DJ Wozza @ Nov 10 2008, 12:31 AM)

Tango has some very nice 19's on his IS250 I think
20" dia. will also fit if you can cope with the thin sidewall. It isn't the diameter (within reason) that determines whether they'll fit or not, but the width and offset.
Here's my 19" offsets and widths with the difference in clearances from the standard fitting.
Wheel Size (diameter and width): 19x8.5 Front - 19x9.5 Rear
Wheel Offset Front:+38..offset extends +13mm to standard/+1mm inner gap
Wheel Offset Rear:+42...offset extends +42mm to standard/-16mm inner gap