Hell, you can feel the undulations at 90, particularly the South East quadrant (where I've spent most of my time). Not sure I'd want it as a track, bit too long, even in a Veyron or X1..!!
Speaking of long courses, how about the A3(M) from Guildford to Waterlooville..?? Dual carriageway, with long sweeping corners and ever changing elevation.
A number of years ago, I spanked a car of mine into the Armco. Once I got it back, I needed to regain my confidence. It was a flightly little monster anyway and after having spun it, I was nervous. At the time, my Wife (to-be) lived in Kent, I lived in Portsmouth. I drove back from hers around midnight and kept my foot in for the entire journey. That section of the A3(M) from Guildford down did wonders for my confidence. My poor little car was still huffing and puffing when I got up to go to work the next day
Failing that, how about a quick blast across the Moor?? Two Bridges, Yelverton, Tavistock and back. 21 miles on B Roads...
{Cy}