It was rainy and dark on the E4 at the height of Årsta in eastern Uppsala that morning and the man has stated that he was on his way to a workshop because his catalytic converter broke down.
The car therefore sounded loud, but the man chose to still drive on E4 when it was not more than half past five in the morning.
He was driving at about 60 kilometers per hour on the road - the maximum speed was 110 kilometers per hour - when a female driver suddenly drove into his car from behind.
No one was injured, but both cars were damaged.
Must adjust the speed
A police patrol arrived to write a report and then saw that the man's car lacked working taillights.
The man himself has denied that he was guilty of any crime.
The Uppsala District Court states in the judgment that the motorway certainly only has a maximum permitted speed, and not a minimum.
But that drivers are at the same time obliged to adapt their speed to "what road safety requires".
The man is sentenced to a 40-day fine of SEK 200 each.