While I think that driving on a track does use *somewhat* more in the way of consumables than driving on a road (although I must stress that I take it real easy and hold traffic up on both) I think there is an awful lot of unnecessary worrying about wear to the car here and more so on E38.
As Nick's said - Santa Pod is super-grippy, but people are also doing standing starts on it - huge loads on their cars and lots of resultant failures.
The second biggest risk with a track day is not mechanical failures, it's talent failures, which can and do occur at speed and when trying to change direction (unlike on a strip).
To be totally honest, if you can't afford to risk what you have by taking it on a track, then don't. These short sessions are more likely to tempt people with VERY poorly prepared cars, which are far more likely to fail, or vomit fluids on the track.
The other people out there on a track are your biggest risk, second only to going out and finding your talent bucket unexpectedly empty mid-bend.
That said, I took my Passat out for a lap of the 'ring with the kids and wife in it and I was using it as the tow car on that trip, too. Eggs? Basket? Eh? That was only when the track was quiet and I'd just come back from a previous risk, so had a pretty good idea about what was going on out there. Still, not something I'd be keen to do again!
