Great mod, in conjunction with the various British track mods and a VR headset it brings back great memories of doing track days in my own Caterham-esque kit car.
On that subject have you thought about doing a variant with a motorcycle engine? Caterham themselves made a model with a Fireblade engine that weighed under 400kgs and quite a few have been converted using Suzuki Hayabusa engines. I've had a go at making a tune myself with rudimentary weight, gearing and engine output changes but I don't pretend to know the ins and outs of AC car mod creation so I'm sure it could be massively improved upon.