Hi Catboy
Just to tell you of my experience : I'm new to Porsche ownrship having just purchased a 1998 2.5, 19k miler in April, privately. As I live in London most of the Boxters I looked at had quite low mileages as they are really weekend drives. But they were tatty in the sense that most were probably washed once a quarter in the local carwash and hoovered probably less frequently! Also there tended to be a few knocks on bumpers and kerbs here and there. Many had clutch replacements (stop start London traffic) and I think due to the (highish ) 1st gear with light flywheel mass, more revs have to be applied to avoid stalling.
Things I checked for were the obligatory oil leaks, major bodwork repairs (door/bonnet seams s/be straight), hood closure smooth. Also checked all the stickers were where they s/be : I believe many Boxters suffer frontal damage so check stickers and seam welds at the front. When driving I checked steering free play, wandering, pulling to the side on braking etc. Most drove really well -even high mileages, but what I did note was that the clutch and gearchange varied a lot. Some had very stiff gearchanges and or difficult to change gear. This is either due to clutch on its way out (not releasing fully) or probably gear linkage not fixed correctly when clutch changed. All the engines sounded really sweet !
However what astounded me is how resilent the paintwork and hood are. These cars were mostly kept outside in all weathers as garage space is expensive, but once polished and cleaned with tlc the cars can look almost new !
My car had collected sap tar and all sorts. The paintwork was rough to touch. I had to use an electric buffer with 3M hand glaze (like T-Cut) followed by some Carnabau wax.
The rear plastic screen had misted up. This was treated with Plexus which removed nearly all the haze. Oh and concerning the hood chop : I never open the hood if the temperature is cool. When I'm off to work early mornings I let the demister run on high heat to warm up the cabin for a few minutes and this in turn makes the screen more flexible. Then I open the hood - (never bother with the chop - looks poncy in traffic !). I make sure the screen is treated weekly with the Plexus cleaner. You will also find that the creases "iron" out in hot weather (as it says in the manual).
For the hood I used Porsche cleaner followed by Porsche conditioner. Water now beads off the hood ! (Never use jet wash on the hood!)
The interior was hoovered and cleaned with Sonax cleaners followed by VW leather conditioner. This leather conditioner is UV protecting so protects the leather with strong sunshine and the hood up.
Regarding the alloys, they are also very resilent. DO NOT use ordinary wheel cleaner - highly acidic - will damage. Use the Porsche cleaner as PH balance neutral. If the wheels are bad always by 2nd hand of E-Bay!
So far really enjoying the car. Its is really easy to over rev such is the smooth boxer engine but the steering response is fantastic - almost go kart in feel.
Good luck with your search.
[8D]