Some things that spring to mind:
See if any of the suspension arms have been changed.
At that mileage the various ball joints will be worn.
On the test drive the steering should be light and any clunks or bangs going over potholes and speed humps mean worn joints, which can get expensive.
If it has full airmatic, make sure it rises when the button is pressed and the car is sat evenly when on flat ground.
Try and see the car first thing when it has been stood overnight and not started, to check the airmatic is not leaking and lowered itself.
Make sure ALL the electric toys work.
There are a myriad options available so I cannot list them all.
Dynamic seats can be problematic with leaks and pump issues.
Heated seat should warm up quickly, both bum and back.
Check the date of the navigation disc as they are £190 to get an up to date one.
Engine wise, check the injector seals are not leaking and covered in black gunge.
There should be good thrust from the engine when you press the pedal and minimal/no smoke from the rear end.
That should be enough to be going on with and I am sure there are other things to check but a well looked after S211 will do many more miles as long as it is regularly serviced and well looked after.
If in doubt get a good indy to check it over and give you a report. Money well spent.
Tony
