Help reduce UK insurance prices

[Vee]

I had a friend who was reversing off his driveway, on either side of it on the street were rows of parked cars, so minimal vision. A car bumped into him at about 15mph, they took each others details, he took pictures of their car and his. 3 hours later, he looks out his window, fire engines, police, ambulances. The car that hit him had come back and parked up, all 3 occupants claiming they had back injuries and were subsequently cut out of the car after the roof was chopped off