Hi, the S40 is a good all round family saloon, the 1.8ltr engine is reasonably quick and very quiet, when you go to view the car lift the bonnet, on the engine cover it will say either GDI or Volvo, my personal preference is the volvo engined 1.8 but having said that, if you read the posts relating to the GDI engine you will find many very happy S/V40 GDI owners who claim trouble free motoring and mileages in excess of 100k. Check if the car has a comprehensive service history as this will go a long way to determine how the car has been looked after, if the mileage is around or past the 80,000k mark check to see if the timing belt and serpentine belt have been changed, if not be prepared to part with a large wad of cash to have it done. Other than this look for any signs of accident repair work(overspray) and listen for any unusual knocks or rattles when the car is driven.