Do you mean which currently manufactured cars are made in Britain? Or which want a list of all Bristish car manufacturers ever?

Currently the following manufacturers have (some of at least) their vehicles manufactured in Britain:

Landrover (Inc. Range Rover)

Jaguar

Rolls Royce

Bentley

Mini

MG (although parts are shipped from China)

Ford

Vauxhall

Morgan

Nissan (not all models)

Honda (not all models)

Ariel

Lotus

Bristol

Caterham

Ginetta

Noble

Radical

Westfield

...there are possibly a few other smaller manufacturers that I've missed.

Hopefully that helps?

Rob