You can trigger the system from the key fob so that when you get into the car it's already nice and cool.

Toyota says it can reduce temperatures from 80C to 45C. (Even so, I wouldn't want to drive a car that was 45C inside.)

The solar panel system means you don't need to turn the air-conditioning on full blast, meaning you use less fuel.

But since the Solar Pack costs £1,450, I'd opt for the old-fashioned, cheaper, fuel-efficient method of opening a window.