Part of the entertainment is that it's presented as though it is factual TV. Sure if you look at a lot of their antics you can tell they're staged but a large portion of the viewing public doesn't realize this and their impressions of the car will be tainted by what is essentially a misrepresentation of the facts.
Top Gear to me is like the Tonight Show of cars. It's entertainment.
Top Gear shows like two practical cars per season among all their other silliness (which is what I actually watch it for, the silliness because it's entertaining).
Ironically isn't the fastest car around their track an electric car? The electric version of the Ariel Atom?
I think he also owns a 100 year old electric car, where the motor and battery technology today is really not that far evolved from it, sadly.
(oh here it is http://www.popularmechanics.com/cars/jay-leno/vintage/421594... )