You must notify the Connecticut Department of Motor Vehicles (DMV) within 48 hours so future tax bills can be sent to your proper (new) address.
Since taxes are in arrears, you should notify the Westbrook tax office.
Motor Vehicle bills are based on any given October 1. For example: if you live in Westbrook on October 1st but move to Middletown on October 2nd, you tax bill is due in full to Westbrook. Failure to receive a tax bill does NOT invalidate the bill or any interest which may accrue. This is per Connecticut State Statute §12-130.