This is in the book, not the film. Bond has been chasing Drax back to the Moonraker base, and is on the point of catching him up when they go up Charing Hill, to find a Bowaters truck, carry 20 giant rolls of newsprint, labouring up the hill. Drax tells his henchman Krebs to jump on the truck and cut the ropes anchoring the newsprint, which bounces back down the hill and smashes up Bond's car.