Hey Emm,
I guess its worth checking that its had the front springs replaced, as this seems a common problem, along with the little things like the electric mirrors working correctly. If the front tyres aren't brand new it'd be worth trying to haggle for a new set, ours eats them at an alarming rate! The electric windows on ours have a nasty habit of going up and down very slowly, so I'd be looking out for that too.
When we got ours we noticed alot of the multiplas had paint damage on the edges of the doors where folks had forgotten how wide the car is and how large the doors are, so might be worth a quick check.
Other than that, a good test drive and check the smile on your face when you get back to the garage, always a good indication!
Brillient reply thankyou thank you thank you!!!