The six were Desmond Avis, 67, Alexander Koen, 26, Karel Harmse, 21, Michael Ram, 25, Jacques Senekal, 33 and Ntisikelelo Songesi (age unknown).
The six were all accused of driving while under the influence of alcohol.
According to the asset forfeiture unit's regulations, police have the right to seize a motorist's vehicle if the driver's blood/alcohol level is more than three times the legal limit of 0.05g/100ml of blood.
The unit's advocate Willie Kingsley told Die Burger that, theoretically, it was possible to seize the vehicle of every drunken driver, but such action needed to weighed up against the seriousness of the situation.
Police 'have the authority'
He said that confiscations would be made of vehicles where the driver's blood/alcohol level exceeded the limit by three times and where there were previous drunk driving convictions.
Vehicles would be seized also if the circumstances were of serious nature such as reckless driving or culpable homicide.
Superintendent Johann van Greunen confirmed on Monday that police had the authority to seize vehicles.
Van Greunen warned motorists there would be an increased number of roadblocks during the festive season in the Port Elizabeth area.