I am thinking of getting one this winter and turn it into a track car. I was thinking more along the lines of a CAT D car though as you can have a decent one for 1/3 of that price and still have minor damage.
I drove my friends 57 plate few times and felt so close to karting. was really good fun.
It seems cheaper to mod compared to the Zed and could loose significant weight also.
however, I cant justify buying one to do what the Zed can do better to be honest with you. its less comfortable and running costs are similar to the Zed.