Grand Prix is not as good as Le Mans, but worth watching. It's a nice slice of 60s grand prix racing, but mixed in with too much sub-story and romance for my liking
I do think they did use some real race stuff in Grand Prix, but most of it was filmed with 6-7 cars. They would just line the cars up and go through the section of the track a few times. Every time the same cars would pass the same opponents. After a good one was filmed they would just move to the next section. Typical Movie Crap Also they used F3 cars that were modded to look like f1 cars thus they didn't have such an outstanding speed.
It was a great movie, also a long...long... movie. Still liked it though. The only bad thing was the way they did it when you saw a side view of the cockpit when the Ferrari crashed, of course, there were no skid marks and the car was still moving at the same speed and same direction.
I noticed that too, and also, when Scott Stoddart crashes at monaco, just before one of the cars gos into the water, when watching the car do the "wall ride" if you know what im talking about, you can see the hydrogen cannon used to propell the car with the dummy in it, you can see the end of the cannon and the white vapour produced for about a second.
I also read somewhere that there was going to be a clip from the nurburgring, but when phil hill went out to do qualifying with the onboard camera, it fell off whilst going round the karrousel :shrugspelling).