Mk4 seats need welding as the track is wider than the mk2 and mk3 and also the front mount is totally different the Recaro ones have a bar so it's just a case of chopping off the mount and shifting it along a bit

I have mk4 seats in the front of my mk2 and the backs are going in shortly. I just went to a breakers with a generator, an angle grinder and drill and robbed all the seat brackets which cost me more than the feckin seats did!!