window fog spring.

[Festively Jolly]

hey list!  ok i have read about the  fresh air spring in the 5000 and
200 i think. but never heard anything about it for a 1988 Audi 90. well
that's what i own and the symptoms are EXACTLY like the ones for the
broken fresh air spring.  so the question is... are the springs the same
for the 5000 and the 90?  could i just get the same replacement spring
they make for those cars?  
also. i cannot even find the damned thing. i didn't see it where they
mentioned to look in the 5000s.  any help is appreciated now that the
weather here is getting a lil nippy :) thanks!