What to look out for when buying?

Please list the things to look out for buying and veiwing one of these great cars..

With a lot of these coming on to the market in various forms private \ trade and auctions.

I thought some of you owners could put some tips on here for buyers.

It would help create something like a :-

"Buyers Guide for the Mk10 \420G"

Im sure someone was going to start a buyers guide, come on guys I think it would be a good addition to the symposium.

I think problem with this idea is alot of the problems we experience with these cars are not there when your looking at buying them, they show up after 6 - 12 months of driving.

The only buyers guide issues would be where to check for rust, and giving the usual mechanical checks. I cant think of any particular part of the car that requires special attention.

A compression test would be a good idea, that would show how worn out it is or perhaps suspect vavles.

Are there particular parts that are hard to find/replace if the ones on the car you're looking at aren't up to scratch?
That would give buyers an idea of which ones to avoid and what they could bargain on.
There is a car in Australia called the Leyland P76 and with those, there are some external chrome trim items that just aren't available any more and many cars no longer have them fitted.
As the Mk 10 & 420G has been out of production for so long, I presume there would be similar things to watch out for when looking to buy.