Here is good text, from this site:
On the left menu: Miscellaneus -> Trading Advice
...and this is from the http://www.alfa156.net
site Left menu: Tips -> Buyer's guides:
Check that Air Con is working
Look for corrosion over windscreen and on roof
Listen for clunks from front ball joints
Cam variator rattles from Twin Sparks (read more here http://www.alfa156.net
Check for flaky paint on front bumper (read more herehttp://www.alfa156.net )
Make sure rear brakes haven't seized/corroded
Check if all interior/dashboard lighting is still working
Check engine under tray isn't smashed - it'll ground out otherwise.
Check suspension for creaks over bumps (read more here http://www.alfa156.net
Check alarm arms properly
Check for oil leaks (it stungs a fortune for leaky balancer shaft seals)
Run air con on coldest setting whilst you test drive it then feel round
the spongy gasket on the plastic housing in the middle of the bulkhead to see if it gets wet.
Test drive it in the wet and go through every puddle you can find - then check
the carpets for water. (read more here http://www.alfa156.net
If you're buying from a dealer dont take the warranty if its a WHA warranty (they're 5hite)
Check edge of drivers seat for wear on the piping.
Check when the cam belt was last changed! (read more here http://www.alfa156.net