The rears on my B6 have been a pain to take off the two times I've done it so far.
Just a liberal dose of kicking to alternate sides of the tyre managed to loosen them off.
BTW, I read somewhere NOT to use copper grease as it attacks the allow. Don't know what you should use though.
The first time I had to take the rear wheels off my GTI it took me nearly 45 minutes per rear wheel to get them off..Galvanic corrosion apears to be the cause - almost cold welding the alloy to the iron hub.
All you can do is as Macduff says..kick alternate sides, and if you get the car up on axle stands, kick from underneath, outwards too.
Just make sure you have someone waiting to catch your allow before it lands face down on the driveway!
On the subject of Coppaslip or similar...I always use it.
Porsche specifically state you use it on the raised lip of the hub (where the wheel locates), threads of the wheel bolts and under the shaped washer (between wheel bolt head and rear of washer) when replacing wheels.
I'm not aware of an official VAG policy on it, but the local Audi, VW and Skoda garages I've used, all Coppaslip the wheel bolts and hub lip to prevent corrosion.
Also, in 18 years of cars with alloy wheels, I've never seen and corrosion when using Coppaslip.
