You can still get MK5 with relatively low mileage just look for one with full service history preferably main dealer but that could be pipe dream. but service history is good.
just make sure its had the cam belt/water pump replaced and if not the price should reflect this.
Make a note of how many owners the has had, higher the owners could possibly mean maintenance not being carried out.
general condition is a massive give away, for instance pull the seat-belt out and if it retracts of if own accord then that's plus point. if it stays out its being well used.
check all the tyres as this could be a big expense.
there's loads of stuff to look for TBH