I did one of these last year, not in a Lambo but I got to drive an Audi R8 and a Aston Martin Vantage around brunters!
To be honest you dont spend a massive amount of time in the cars but I didnt expect to for £80 a car (£160 for the full day including videos/pics etc). Got 3/4 laps in each, 1 sighter and 2/3 hot laps!
Saying that though, we turned up fairly early in the morning and didnt leave until it was dark so we got good value for money in terms of a day out!
Would love to do another, would be the lambo/ferrari package if I did another one!
Great idea for a day out!