I am installing the same deck in my '02 GTI 1.8T and went through ebay to get my wiring harness and dash kit. Check out this store in particular "Autoware302" then check under VW Jetta and it will bring up wiring harnesses custom fit. You would need "Vw Jetta Golf GTI Car Radio Wire Harness Stereo BHA1784" Sadly i can only find '01-05 dash kits for the jetta.
Hope this new info helps,
if not disregard

Link will only work if you have an ebay account

• http://search.stores.ebay.com/Autoware302_vw-jetta_W0QQfcdZ2QQfciZQ2d1QQfclZ3QQfromZR10QQfsnZAutoware302QQfsooZ1QQfsopZ1QQfsubZ0QQftsZ2QQsaselZ226341785QQsofpZ0QQssPageNameZRC0021