Have a test drive in it and check if there's any odd clonking noises from the steering wheel, Steering Rack failures is a bit common in the MK5 Golf and are not cheap to fix. Obviously check for any lights on the dash, ABS/ESP lights can indicate faulty ABS pump while the Engine Managment light may indicate a clogged up EGR valve.
The FSI engines are fuel sensitive and runs optimally on Super Unleaded which is quite an expensive affair for an economy car, ideally you should use 98 RON rated fuels or higher which is either the Tesco 99 fuel or Shell V-Power. You can put standard unleaded in but the car will run flat and may lead to premature failures or misfires on the engine in the long term. Plus bear in mind that even though it is a 1.6, the Car Tax is quite high as I think it's £200 now for annual road tax.
But generally the 1.6 FSI is a decent car and I shouldn't be too worried if everything looks to be in order (including service history). My own 1.6 FSI had done around 66600 miles now and it hasn't missed a beat.
