I'm actually planning something like this atm with a few mates from work. Nothing particulary high powered but all good fun. I'll have my BMW, and the other 3 will be driving a VW Golf (Mk 3), Ford Fiesta and a Honda Civic.
We plan on going from here to Amsterdam, to the Nurburgring and onto the Stelvio Pass. If funds allow us to go further then we plan on going to St Tropez, then Barcelona and then onto Madrid. We'll end by getting the ferry home.
If funds don't allow then after the Stelvio we plan on by passing Paris on our way back to the UK.