I have to say I'm a teensy bit skeptical of the '8hp' claim. One horsepower is 746W, so to get 8hp you need nearly 6kw which means pulling nearly 25 amps through the 13A socket.
If it does produce 8hp, it either does so for extremely short periods, or it's capable of over-unity energy generation - which would make it a truly massive bargain!
As to whether it's any good as a car dryer, I have no idea, but I would think that you'd need something pretty powerful to dry a car off in a sensible amount of time, and if one doesn't have a leaf blower then this might fit the bill.
