hi there i have just had audi rs4 replica 18's fitted to my t25
i needed to have the centers bored out to 60.1 mm on the front wheels only.(as they are 57.1mm from new)(also had to remove the 2 grease caps on the front and grind the lip down so the wheels went over)
then i had to have 6mm spacers for the fronts so they didnt catch the wishbone.(longer bolts come with the wheels)
as to the rears longer studs were needed i used bay window front wheel studs(very easy to swop over)(you dont need to bore out the rears they fit straight onto your drums )
i still haven't figured out yet how to put the center caps on but ill get there
hope this helps