Need to rent a car in London ,got the International Driving license

Hello fellow Expats

could you give some suggestions about driving in London,
I know it's expensive but I'd love to test drive those expensive machines
let me know if you have done it before or any place that can rent the car for visitors.

Do you mean hi spec sport cars?

Its not London, but Silverstone might be what you want - silverstone.co.uk/experiences/driving-days