Fella I don't want to argue with you but Lotus's own test track is pretty flat.
They went to the TG airfield and surveyed it and then planned a circuit with testing corners. Each one designed to test different aspects of the cars handling. 5G use better tracks but they use different ones each week. Sometimes cadwell, sometimes Combe, sometimes bruntingthorpe etc etc. Great for testing a car in it's own right but TG use their track to benchmark all cars against each other on a reasonable level playing field. The only variables are the weather as they use the same circuit and the same driver each time.
Hills a rwace circuit do not make! I've done a couple of track days on air fields and they're ust as hard and challanging as popping up over avon rise and getting a bit sideways under breaking into Quarry at Combe.
Nick