Damien Price, 30, mowed down Sgt Alex Howden at a Sainsbury's in Exeter
Sgt Howden suffered a broken leg, along with head injuries after hit head on
Price had already attacked and reversed into a couple in a spate of road rage
Shocked onlookers managed to stop Price fleeing, before he bit another officer
He was jailed for six-and-a-half years after admitting GBH and dangerous driving