if it was a pre-90 you can swap all the backrest and base foam/fabric to the frame off a MK3 Polo GT/G40. its exactly the same but a bit lower. post-90 seats are a different shape so this wont work.
pre-90 the hazard switch is on the dash, post-90 the hazard switch is on the column. it could still be a late registered pre-90 car? also if the seats arnt original they might have been changed too, the way to check is to look at the bolsters they're subtly different. post-90 lower bolsters are flat from the back to a bit further forwards, this means you can comfortably sit in the seats sideways plus they're much easier to fold forward.
check this link out, this seller has 1 90specand 1 pre-90 in the same auction. the one on the left is post-90, the one on the right is pre-90
http://cgi.ebay.co.uk/Golf-gti-seats-Mk2-front-pair-/330518955722even if you have 90spec seats depending on the pattern you could swap just the front seats over as some of the trims were available for both years, liek the one above plus the rainbow trim
