I doubt in todays climate that a buy British campaign would be allowed,
I see today, that Britain's new richest man is not full on supporting, but stating in his opinion that Britain doesn't need Brussels. when you got zillions its easy to say it !!!!!!
To answer your question i like to go for best value, and with place of manufacture not really considered, i bought a new car a few months back, not made in Britain and i don't believe that it has any significant British parts, the length of warranty was the deciding factor.