Problem areas are well documented on this site: dodgy egr valve, sticky windows, camera not working.
Also watch out for shock absorber bushes and rusted out bumperbar (they can come off in your hand). Do make sure you get windscreen replacement on you insurance (?1000ish).
I've had every one of those (including bumper bar rolling around inside the cladding and an £860 windscreen on my insurance) do I get a special sticker or something?