It is interesting that you would choose this as your leading example here as it does not attribute this torching to migrants or immigrants. It lists no perpetrator.
So, how much are car burnings attributable to the recent surge of migrants? Here is a quote from Washington Post:
"But when it comes to intentionally setting fire to cars, said Manne Gerell, a lecturer in criminology at Sweden’s Malmo University, such incidents have increased “big-time” over the past couple decades — but not in the past two or so years. Across Sweden, he said, about 1,500 cars are burned each year. The reasons can include insurance fraud, hiding other crimes, social unrest and “random youth vandalism,” he said."
Basically, he states that they haven't really seen a significant increase in car burnings from the recent migrant surge, however, it does seem that this phenomenon is largely homegrown. While information may come out in the future regarding this event, it is important to take it all into perspective.
It is also important to look at the numbers outside of simple anecdotes for other types of crime. Lets look at homicide data. In 2017, the homicide rate in Sweden was about 1.15 (per 100k). In the USA homicide rates are somewhere around 4.5 (per 100k) (from what I can tell, 2017 data isn't out yet, but
While anecdotes are scary, the numbers consistently suggest that Sweden is significantly safer than the USA (and certain cities in the USA blow it out of the water).