OK, plates are a bit different, though. From the previous comment I thought the extra tax was a sales tax (which is in general not the same as registration fees

OK, plates are a bit different, though. From the previous comment I thought the extra tax was a sales tax (which is in general not the same as registration fees). But I imagine governments always find ways to prevent competition that is not to their advantage (I.e. it seems that free flow of cars is actually restricted as per other reply to my previous comment)