This is a bit of a difficult one, as there's not too much to worry about, which is excellent news for you. So, provided you're buying a car with full service history, you shouldn't be in for any nasty shocks but check that the electric windows, locks and sunroof all work and that the air conditioner produces chilled air – fixing such items can be pricey.With turbo diesels, check for excessive smoke on hard acceleration - it could be a sign of worn turbo seals. Generally, though, these engines are trouble-free if the oil has been changed regularly.