Don't forget Caterham, Westfield, Marcos, Noble and Ariel. I belive these are all still British, although very small and catering for sports car nuts only.
I've long been a Lotus fan but they are owned by Proton these days, the same guys who now own Kenny Roberts Moto GP team.
TVRs are like Guzzis- unique with lots of character but loads of faults and niggles in comparison to say, a Porsche.
Guy