because all the parts can be swapped around and usually do end up on the wrong cars it's very difficult to tell if it's a gti. because of this I'll try and say which parts came on the cars when they were born.
4 light grill, like someone said before. None of the Gti's were born with twin lights.
n/s wing mounted ariel. 16v's had this relocated to the roof (and both my 8v's did too). All the rest of the mk2s had theirs on the wing
big bumpers. the last batch of mk2's had big bumpers, but the gti's had a deeper spliter compared to the drivers big bumpers.
drivers with big bumpers didn't have fog lights on the front. the hole was filled in.
the engine obviously. only the gtis had injection. the last run of drivers and syncros had 1.8 carb engines. 88 on onward 8v's had digipants injection. the 16v retained the k-jet setup until the mk3 arrived.
the 1.3's had 4 speed gearboxes. all the rest had 5 speed.
Black plastic arches. All GTi's came with them aswell as the last run of Drivers.
90 spec mk2s with big bumpers had extra skirts attached to the sils.
only g60 mk2s had g60 arches - funny that

gti's had more 'sporty' seats which held you in round the corners.
all gti's had rear discs.
88 and onward 16v's had 256mm front discs compared to 239mm ones on the 8v.
Rear spoiler. All GTi's. Quite often removed for that euro look.
twin exit exhausts. only the gtis had them.
various gtis came with half smoked rear lights. mostly 16vs iirc.
the last run of mk2s came with 15" BBS and PAS as standard
Did I miss anything?
