"Before starting, I would recce the line and check that there is nowhere the car will deviate two or three feet from the line.

"The gearstick and handbrake should be covered in foam and I'd make sure that the guy who's driving is as far as possible on the right-hand side.

"If I'm going to go into an open-top car, I want to know that it's a car with as straight a windscreen as possible.

"I'd also try and take out the passenger seat because the chances of landing on the back of the seat or the headrest are quite big. I'd remove the headrest if I couldn't take the passenger seat out, or lay it down to act as a bed.

"You really want a convenient take-off platform on the train and a grip for your left hand, so you can lean out. The actual jump itself is very much dependant on the speed.

"If you're jumping in to fight with the bloke, you can take advantage of that and use him to save yourself and grab him round the neck.

"It's a leap, so there's no technique to it. You've got to allow for the fact that you've got a headwind and you're jumping further than you would in a stationary environment.

"It's a question of getting your feet into that relatively small area between the back of the windscreen and where the boot starts.

"The guy who's driving the car is the critical thing. He's not going to be watching you, he is going to be watching his mark on the train, so you have to nail the leap.

"To have some fun, you can get up to 40 or 50mph. Forty is best because, if anything goes wrong, you've got half a chance. But at 50, if you hit it and bounce off, you've got a lot of problems.

"It's getting that fine line between stepping into a car that's two feet away or having it about eight feet away. Because if you leap then, you'll come off the side of the car and really hurt yourself.

"I've done the stunt so much over the years... on Octopussy, and even and even on Bergerac many years ago. My abiding memory of that one is trying to get as big a car as possible.

"They wanted me to do it in an MG Midget, but I had to convince them to try and get hold of an open-top Granada.

"The smaller the car, the smaller the chance that you have of actually making it. If that happens, you're going to roll off, or worse, impale yourself on the windscreen."