Look out for the following items
1. Is the AC functional? If you have a leak at the evaporator it is mucho
bucks to fix.
  Look for any evidence that it was possibly just charged just to get rid
of the car.
2. Check out the hard top release and soft top functions very carefully.
Does everything work smoothly without a lot of banging and crashing? Look
for any evidence of hydraulic leaks especially around the windshield top
frame.
3. Run the power windows all the way down, then up. Is everything nice and
quiet and smooth. Most of the ones I have seen need new regulators.
4. Depending on miles the motor mounts should probably be replaced. Also the
rubber exhaust hangers.Flex disks in the driveline too.
5 .Try to stay away from the self leveling uspension system. Lots of bucks
if you need repair.
6. I am personally  happy with the 320 engine. Good power and economy.
7. Check the condition of the rotors and brakes. If the pads are down you
will probably wind  up  replacing all four rotors also.

That is all I can think of right now. Hope it helps
Peter