It would have been good to meet, ah well.
To be honest though guys you can hire pretty much anything you like at the ring. There are rent-a-racecar companies offering Scirocco and GTI based track cars (stripped, roll cage, bucket seats and DSG - probably to protect their engine more than to showcase the gearbox or help the driver).
Or if you fancy something smaller there are Suzuki Sport models with similar setups (minus DSG obv).
For rear wheel enthusiasts you can get old BMWs, 350zs etc.
And then there are more focused track cars like Caterhams and the like. There really is something for everyone.
BUT...
A standard GTI is more than up to it. So don't feel you have to rent. Part of the satisfaction for me is taking your own car round. The most important modification for going round the Ring is to the driver... and it's realising your not a racing driver (especially on your first laps).