Or for a tenth (-ish) the price, there's another solar panelled car. Very tempted by it. Also reminds me of a car, can't think which one...
Until batteries improve their power/weight/volume ratio the rest of the car has to focus on them, which lets be honest, is one of the things that draws us to the A2 in the first place.
Bearing in mind local weather conditions (Central Scotland) during most of the year, a car fitted with a roof-mounted combination of a micro-wind farm and mini-hydroelectric plant might be the best option?