A4 vs A8 wheels again ... 4 5kCSQW

[steveb@falcon.kla-tencor.com (Steven Buchholz)]

... Thansk to all of you that replied to my earlier query!

OK, now I've seen the wheels side to side and know the differences 
between them.  The thing is that the A8 wheels have a different 
offset from the A4, but the A4 wheels have the same offset as the 
OEM wheels (45mm vs. 38).  I've never considered this sort of thing 
before, so I'm a bit clueless.  It seems to me that even though the 
wheel is 7" wide instead of 6" that I'd want to maintain the same 
offset, so the A4 wheels would be the choice.  Can anyone point me 
to somewhere that I can figure this out?  [This reminds me that I 
wanted to put "Race car Vehicle Dynamics" on my Christmas list ...]  
I'd also appreciate hearing back from BTDTs ... will tires on the 
A4 wheels rub because they don't position the inner edge of the tire 
far enough?  Would the A8 wheels rub because they stick out too far?

TIA!

Steve Buchholz
San Jose, CA (USA)