
The makers of the movie were actually given the prototype DB5 (Chassis No DP/216/1) to use in the movie. Another 3 DB5s joined the Bond stable for use as road cars or in subsequent movies ('Thunderball', 'Goldeneye', etc). John Stears actually cut the hole in the roof for the ejector seat in the prototype!
For those of you interested in the Bond DB5s I can thoroughly recommend Dave Worrall's 'The Most Famous Car in the World' (ISBN 0-9517509-1-7).