www.jec.org.uk

I was recently fortunate enough to be invited to a driving day at Palmer Sport Bedford Autodrome. This is a purpose-built trackday complex run by Jonathon Palmer of F1 fame. There are lots of interesting (and fast!) cars that you are urged to drive as fast as you are sensibly able around several different courses with an expert instructor alongside. (For example, Lewis Hamilton worked there for a while until he got a better job!)
There are Porsche 911's, Renault Clio Cups, serious single seater racers, Caterham Super Lights and a 2 seat racer powered by a 3.0 V6 Jaguar engine.
The highlight of the day for me was the GT3 XKR. This is a stripped out and race prepared full-bore XKR. It's seriously fast and the noise is to die for!! Full-on V8 growl and a super-charger whine as you wind it up well past 130mph!! The auto throttle-blip as you change down charging into a corner is one of the best things I've ever done with my clothes on!
These things are so powerful that they had to extend the circuit!
If you get the chance to go jump at it!! Anyone can do it as long as you're over 21 and have a driving license and have saved your pennies! It's not cheap so most go there on corporate days but i'd be prepared to pay my own money to go back - it's that good!!
More info on www.palmersport.com
There was an article on it in Jaguar World a few months ago.

Splendid, I have to agree, it is a fantastic experiance.
I am lucky enough to be involved with tuning the engines for these marvelous cars and get to spend a small amount of time on the track.
They are not actually gt3 cars but purpous built for Palmer, although they have full on race suspension, brakes etc.they also have air con to keep customers comfortable and a passenger seat for the instructor!
Although the engine is tuned for the job, it is still mechanically a standard XKR engine, a testement to the brilliance of the Jaguar V8, an engine that I am increasingly impressed with.
In fact I would reccomend a test drive of the standard XKR too, huge fun.

I went back again last week - still absoluely awesome!! I can't recommend it enough - an unforgetable day out for a petrol head!!