Well, there were Hooligans burning cars. Those don't care about politics.
Then there were those left anarchists who attack shops to burn the TVs in them - anti-capitalists or more anti-consumerists.
Then there were those who, after seeing that, looked at each other and then entered the shops to take out the TVs to steal them. Consumerists you could say ;)
Then there are those who wanted to get provoked by police, and by lo the police played their part here.
The problem starts when you want to know how many cars have burned. I have only seen the result of one ca. 40 people big group walking through Hamburg for 10 minutes without any police stopping them. Those were there to burn cars (and indeed did nothing else on an empty street in the morning).
Until I see any other proof I consider them Hooligans. It is not normal even for the militant leftists to do that, especially in the middle of a living area and in that case I think in the center of "leftism" in Hamburg. The (German) militant groups have also released statements condemning that.
How many cars burned in other places - I have found no numbers.