Going to buy a mk3 golf as a tow car for my bike when taking it to the Nurburgring & a wet/damp weather track car for when it's a bit hairy to be out on the bike.
Similar to a guy I saw there in July - he had an M5 tow car for his Ariel Atom. Well kind of the same

If you want a quick car round the Ring, seriously consider a Mk2 GTI - 8V or 16V, or even one with a 20V turbo conversion. Any one of them will tow a bike without any problems, and, in stock form they handle waaaay better than the stock Mk3, which, IMO, handles round a track with all the finesse of a tub of Flora.
Yes, you could spend a mint on mods on either car, but you'd be doing that anyway.
Mods you need to consider straightaway are brakes (disks and pads), plus anti-roll bars. Both relatively inexpensive upgrades which will change your enjoyment of any track. Brake fade on the Ring is
horrible!