I sold my car last year, why am I still being taxed on this vehicle?

The current tax bill is for any and all vehicles registered from January 1 through December 31 of the previous year.  For example, the 2012 tax bill that you received in July of 2012 was for any and all vehicles registered at any time between January 1, 2011 to December 31, 2011.  The bill will be issued by the municipality where the vehicle was registered on December 31 prior to the July billing.