SACRAMENTO, Calif. -- A joint effort by a California state tax agency and the Department of Motor Vehicles to detect tax fraud by unregistered car dealers has collected more than $2.8 million in new revenue for state coffers, reported the Sacramento Bee newspaper.

The state's Board of Equalization is working with the DMV through a workgroup formed in 2007 to stamp out untaxed used car sales by unregistered dealers. The group's members share sales and vehicle ownership information, identify unregistered licensed dealers, work on enforcement sweeps and help each other perform audits, DMV director George Valerde said.

The amount recovered is small when measured against the state's estimated $2 billion a year tax gap, but "every dollar counts," Valerde said in a statement.

BOE spokeswoman Anita Gore said the joint effort and information exchanges are expected to increase over time as DMV modernizes its computer systems and other data collection methods within its existing resources. The cash collected may also increase in future years.

The BOE is a publicly elected tax board that collects more than $53 billion a year in taxes and fees for the state and local governments.

The DMV not only licenses drivers, it collects sales and use taxes on used cars on the BOE's behalf. It also registers and tracks vehicles and boats, investigates fraud and licenses dealers and driving schools.