The only way to check is to get the car up on a ramp, keeping it level, then open the front filler plug. If it just dribbles out, then its full.
Alternatively, when I do the 5th gear mods for owners, I drop the oil entirely and then refill with the specified amount, so that we know there's as much in there as there needs to be.
Cheers,
Mike
PS Use only the genuine VW oil.