4WD is just extra weight to carry even in the wet, for a race spec car of this quality. The aero packages and correct set up mean they have all the grip they need add this to modern full wets and there is not a lot of difference between wet and dry.
I went out for a few laps at Oulton park in a Motorsport Elise that was built for the Britcar comp. It was teaming down and the car had full wets on. It was the fastest i have been round a track in any weather let alone teaming rain, the faster he went the more you could feel the aero dynamics pushing the car down into the track, it was a strange sensation almost felt like oversteer on the bends. If you look at the pic above you can see it has a complete aero package specific to the car, the canards in the front bumper are in a very unusual place suggesting a lot of work has gone into putting them in the right place.
Also if you watch the World Touring cars there is no difference between the front and rear wheel drive cars. It is all about getting every ounce of excess weight out of them. One of the cars that crashed out in quali at Macau was because it had qualifying only driveshafts to save a couple of grams.
The VLN cars are very serious pieces of kit. I was in Milteks golf R ( as a passenger )at the Nurburgring being driven by Richard Marshall who is a semi pro driver and he knows the place like the back of his hand. We were hurling along at silly speeds when a Z4 VLN car drove round the outside of us on a bend up on the curbs and grass.
