Its pretty common for a wide wheel to rub the coilover spring, most guys with M3s have that problem too. You can either use a spacer or get a shorter spring.
Stock ti offset is 46 for the 16x7 sport wheels, M3 is 41 f/r for the staggered DSIIs/Contours.
I run 17x8.5 et41 wheels on my car and they clear the coilover by only a few mm. I can easily see a 17x9 hitting the coilover if the offset is still 41.
Check out posts #80 and 96 in this thread for control arm differences.
http://forums.bimmerforums.com/forum...1343977&page=4