Two other cars were scorched in fires.
Police suspect arson and have yet to arrest any suspects.
“We need good witness information to make any arrests. There should be a number of people who know who lit the fire,” Björ Blixter, a Gothenburg police spokesperson, told the TT news agency.
“There are great values that are fired up. What is worrying is that if we put the claws of those who found themselves in, they have to pay large damages. They mortgage their entire future in this way, ” Blixter said to TT.
Two people were detained on suspicion of previous car fires.
“We thought it would have a deterrent effect to show that one can be arrested and detained for such actions, but it did not,” said Blixter, who is not convinced that people set fires to cars for the sole purpose of “messing around with someone.”
“It could be more criminal gangs who staged this to keep us busy,” said Blixter, who added that is perhaps a means to distract the police force.
The Gothenburg police have the right to use resources from all over Västra Götaland through mid-May to tackle car fires.