You can register a car in the 'Commercial' class if all the seats behind the driver are removed. Instead of the seats, you must install a permanent box or permanent shelf to transport the load.
and how are the changes in vans?
You can register it in the 'Passenger' class if the truck has     at least one side window behind the driver, and     at least one seat or seat accessory set that is installed behind the driver
and these modifications are permanent?