they will fit any top end mkIII (any that have 5 wheel nuts - as do mkIV's, lower mkIII models have 4 wheel nuts) as long as they aren't ecessively big wheels (doubt there will be any) and you have to change the tyres too. what size are the wheels your lookin at? some audi wheels also fit.
i've seen a mk3 gti round near me with some of the standard gti alloys from a mk4 fitted,so i presume they will
The tyres will be 205/55/16 my original ones are 205/55/15 I know the difference of the rolling circumference will now be 140mm. They wont be on long though as im planning on buying a Bora so will swap them over to that.
think you'll get loads of scrubbage with those tyres, you're car will feel really slugish, and yu're speedo will be well out. you need to get somethin like 205/45R16's on there first.
Standard MK3 tyre size should be: 205/50/15. If you have anything else on there it is wrong. For 16" wheels, you should have 215/40/16 tyres on it to keep the wheel/tyre diameter as close to standard as poss. MK3 anniversaries came with 215/40/16 standard.
I have mk4 wheels on my mk2, the tyres were no good though (unless i planned on ploughing a few fields). I had to swap them for 194/45x16's
you rally want 205 wodth tyres on a mkIII though IMO. took a guess that they need 45R16's, stand corrected by S1MMA.
