4K: which parts share with VW GTI A2? (was: 4ks-suspension knock)

[Eddi Jew <jew@rysa.dtc.hp.com>]

I'll have to word this question carefully :) ...

 > It seems that the little lock nut that secures the strut 
 > bearing to the strut was loose.  It is a little nut with two notches on 
 > it that requires a special tool/technique to tighten properly.  This is 
 > below (under) the main hex-nut that can be seen from under the hood. 

This post and others have me believe that there are some parts (trying not
to say "design") similarities between some 4000 models and the A2 Golfs.
Using my '86 VW GTI as an example, which year models? Which subsystems?
For me, it would be nice to know that I can leverage my experiences (good
excuse to use for buying one) and help out on some postings.

If I could still apply a majority of the very-available performance A2 parts
out there on the 4000, I'll get a car with good looks AND affordable
upgrades- then I might replace my GTI. Is there a 4000 that's a 4-door (5-door) 
hatchback (don't know much about them 'cept heard mostly "coupe")? My
wife would really get interested if that's the case. Even I'm starting to
get practical.

Still wouldn't mind a good deal on a 5KTW, though.

TIA.

-- Eddi