I just changed the oil in my T5. I used a 3/8 hex key and it fitted perfectly. Are you using good tools or cheapies? Sometimes you will find that cheap tools aren't the size they say they are.
1992 AXII Telstar TX5 Ghia
121kW 2.5L DOHC V6 in a car that weighs 1100kg's and looks like a 4 banger from the outside......SLEEPER!
1988 EA S Pak 3spd CFI.....Soon to be a 250rwkw HSV eating machine.