BBC: Cars leave me cold, but not the BYD F3DM. I drove it the other day, and it really is remarkable. In one way, it is a rather ordinary compact saloon car, though it did have exceptional acceleration when I put my foot down zooming round the factory grounds in Shenzhen, the vast new Chinese city just north of Hong Kong. This is a plug-in electric car, hence the acceleration, but when the electric battery runs out after 80 miles (128km), the petrol engine switches in …