Audi/VW compatibility and costs

[jknittle@sundown.sdsu.edu]

Hi all,

I seem to remember some talk a while ago about making a list of parts that
Audi and VW shared.  Has anyone any info on this?  Also, some more questions; 

How much can one expect a repair of an Audi, say an 86-87 4kq to cost over
an 84 VW GTI with comperable mileage?  How about frequency of repairs and
cost of insurance?  What are the most common problems with the 85-87 4kq
series?  Thanks for your help

Jim