VW paint is "hard" but i still wouldnt use G3 on it!
If your local to me (PM but i am on the wirral ish) then will PC a bonnet for free to show you the results.
I would start with a clay, followed (if by hand) megs scratch X, AG SRP for a standard non-show car.
If you have the time then megs 83, megs 80, megs gold or 915.