The 85-89 and 89.5-92 bumper styles can be freely interchanged on an ITB Golf since they're all on the same spec line. Hint: the only difference between the bumper supports is one less tow hook, so delete the extra tow hook and all you'd need is the cheap aftermarket front bumper cover, which duplicates the 90 Golf GTI 8V cover.

An interesting question that might only apply to the ITA Golf 1.8L 16V is whether the later cover can be used there too (with hole cut for early extra tow hook, if required). I think it came on some German-built Jettas in 89.5, but I'm not sure if it came on the Pennsylvania or Mexican built GTI 1.8 16V. There was no GTI 16V in '90, and the '91-'92 were 2.0 16V. Assuming for the moment that it did not come on any 89 GTI 1.8 16V, would it be allowed since it's basically just adding the spoiler to the bumper cover? I believe that both the early and late covers would qualify as "integrated", since they cover the original support all the way back to the grille valance. Opinions?

ITCS 8. Body/Structure

b.A front spoiler/air dam is permitted.It shall not protrude
beyond the overall outline of the body when viewed from
above perpendicular to the ground,or aft of the forward
most part of the front fender opening.This body outline does
not include bumpers or bumper mounts.The spoiler/air dam
shall be mounted to the body,and may extend no higher than
four (4)inches above the horizontal centerline of the front
wheel hubs.It shall not cover the normal grille opening(s)at
the front of the car.Openings are permitted for the purposes
of ducting air to the brakes,cooler,and radiator.Dealer
installed or limited production front/rear spoilers/air dams/
wings are prohibited.The spoiler shall have no support or
reinforcement extending aft of the forward most part of the
front fender wheel opening.

NOTE:Integrated bumper assemblies are defined as those
designs where an external non-metallic bumper cover
completely encloses the primary energy-absorbing bumper
and where this cover could be installed in its normal position
with the underlying bumper removed.On cars with integrated
bumpers,the front spoiler or airdam may be attached to the
bumper cover.