I agree - he must drive British cars, if at least as his official 'work' car in the movie. He's the best of British, it would only be right.
James Bond, IMO, needs to have a car that not only has performance, but also some sort of elegance. Some sort of selfishness, such as making it unlikely he would drive anything with more than 2 doors and 2+2 seats (does James Bond carry passengers?); yet elegant enough since he goes to official functions wearing a tuxedo. Nothing that would be showing off, as such.
To me, he would not drive a Porsche 911 GT2, nor a Ferrari F430. He might well, however, drive a Ferrari 575M or a Mercedes Benz SL-class. I'm not saying he should drive those cars; again, British is the way - but just to clarify what type of car I think he should drive. Granted, not many companies are British owned, these days, but at least they should have British origins.