Check service history. Ask why they are selling it.
Ask if there are any faults or any thing that's been fixed recently. Ask if it's had the clutch replaced, probably due soon at that age and mileage.
Check the engine oil, if it's black like bovril- don't buy it.
Remove the oil filler cap and check for Black Death, if it's not had many oil changes then they tend to go black and crusty inside the cam cover, under the oil filler cap.
The variable valve timing relies on a good clean oil supply to work correctly.
Check the cooling system, ask if they have to top it up. Make sure the heater is blowing warm air after road test.