One "overly aggressive" detective sergeant was reduced in rank to detective constable.
However, he and five other officers will keep their jobs at the Metropolitan Police.
The 2008 incident in Edmonton, north London, was captured on film, sparking a probe by the police watchdog.
All six officers, who were armed with baseball bats and a pick axe handle, had stopped the suspected stolen car in Meriden Way on 3 June and arrested the driver, a Met misconduct panel heard.'Unacceptable' behaviour
The panel found the detective sergeant had failed to properly supervise his officers by allowing them to use the weapons.
A Scotland Yard spokesman said: "The five other officers were found to have used more force than was reasonable or necessary to affect the stop by using a non issue baseball bat, hitting the rear offside window causing it to smash."The Independent Police Complaints Commission (IPCC) managed the investigation.
Commander Peter Spindler, of the force's directorate of professional standards, said: "The behaviour displayed by the six officers that day was unacceptable and as such the board has rightly sanctioned them for it.
"The officers abused their position of trust and authority and by doing so breached the high professional standards expected by the public and the vast majority of outstanding MPS officers and staff who carry out their service to the public with professionalism and integrity."
A number of allegations were made during a multimillion-pound investigation into the Enfield Crime Squad.
Sixteen officers and one member of police staff were investigated before prosecutors decided there was insufficient evidence to charge any of them.
The detective sergeant was demoted on Tuesday as the hearing concluded.
IPCC spokeswoman Deborah Glass said: "Officers acting in this way bring the police service into disrepute.
"You do not expect to see police officers smashing a car with a baseball bat.
"Whatever the threat they claimed to experience, their actions should be proportionate and reasonable - which in this case they plainly weren't.
"They breached their codes of professional conduct and their actions were far below the standards rightly expected of police officers by the public."