there is lots more checks you can do but i could be here all day, like putting the car in full lock to see if its goes knock knock knock, this is a sign of wear on drive shafts ball joints etc, go over a few drain covers to see if you get any knocking on the suspension, this can be worn bushes. however, if your going to spend 100 to 1500 quid on a normal used car i'd expect some problems, but if your spending upwards of that then i'd be wary of problems, the last thing you want to do is buy a car for 8 grand and have to put a new engine in it. if the car is under manufacturers warranty and you find a few things wrong, make sure the service history is right then you can take it to the dealer and get these things done for free.