MIT has been working on building Power Generating shocks that can be used to improve fuel efficiency of the vehicles. I've been waiting for this kind of thing for years.
A while ago someone invented a similar thing for shoes that could recharge a battery. Anything and anywhere that there is a natural bouncing motion we can attach a device to generate electricity.
Maybe next is a smaller shock absorber for the drivers seat, harnessing the power of the driver bouncing?