Impounded cars are stored at a Kewdale facility.
A police spokesman said vehicles were impounded for offences including reckless driving and exceeding the speed limit by more than 45km/h.
Operations of this nature are the day-to-day business of specialist Traffic officers, however the Day of Action was a concerted effort between the State Traffic Branch and suburban Traffic officers.
The spokesman said the offences were committed across the metropolitan region and were detected on speed or red-light cameras.
If a car is impounded, the driver of the vehicle is responsible for all costs, including towing of the vehicle and storage fees.
The costs vary, but the typical cost for a 28-day impoundment is about $900 and all costs must be paid before the vehicle can be released.