The unnamed 38-year-old Romanian man had been travelling through Duisburg last weekend when he decided to give his Opel Astra a spring clean - but chose a cockpit cleaning spray containing highly flammable butane gas.
Job done, he decided to smoke a cigarette in the vehicle, unfortunately he forgot to ventilate the car by opening the doors and windows. When he sparked his lighter, the butane-oxygen fumes ignited, causing a miniature explosion inside.
Incredibly, the man escaped with only minor injuries and just suffered slight burns on his face, said police.
The car, meanwhile, came off worse in the explosion: pressure blew off the car doors, the windscreen and the windows on both the passenger and driver sides were smashed.
Following the incident police warned drivers they must always ventilate cars when using cleaning products containing butane.