It is a funny idea that in order to get the car, you need to sign a lease for 20 years. It is a shame it isn't true. What is true is that we at Riversimple will aim for the cars to last for at least 20 years. And we will only lease cars, not sell them. But we intend to offer a variety of leasing packages. For example, someone might sign up to a two or three year lease, at the end of which they can return the car or extend the lease. If they return it we'll offer it for leasing by someone else at a lower rate - effectively it goes into the second hand market. The point of leasing not selling is that we create a business model which encourages longevity - we will build our cars to last.

I thought I should clarify a couple of points on behalf of Riversimple. We have created a technology demonstrator - this vehicle won't go on the public road but will be used for further testing, prior to building a proper production prototype. Yet we believe even this demonstrator would be safe on the roads. It is made from carbon composites. These materials are now widely used in the racing and space industries. They are highly rigid and strong materials and, vitally for us, lightweight. Mercedes and their Formula 1 partners McLaren say they use composites in racing cars because it can absorb five times as much energy in impacts as steel or aluminium. It is these qualities which make composite bodies mandatory for Formula 1 racing cars, and which has contributed to reductions in death and injuries in the sport.