Officers moved in on the garages located on a residential street in Erdington on Tuesday.
Inside, officers found a black BMW 1 Series that was confirmed stolen in March, as well as a bumper off a gold Audi R3.
Several body shells, engines and other parts were seized for assessment by a specialist vehicle examiner.
Officers also found a cannabis farm hidden behind a mirror inside the garage.
Officers arrested three men on suspicion of cultivation of cannabis. They were questioned and released on bail.
Electricity at the property had been bypassed, creating a fire hazard. National Grid attended to make it safe.
A spokesman for West Midlands Police said: "Criminals often use cannabis farms or other illicit activity to generate funds to purchase the equipment they then use to steal vehicles.
"It’s suspected the operation involved cars that had been in crashes, but not deemed repairable by insurers and not recorded on the insurers’ database.
"It’s believed car thieves were repairing the damaged vehicles with stolen car parts, and then selling the seemingly legitimate vehicles online at a discount to unsuspecting buyers."
PC Jake Galley, from the Birmingham Vehicle Crime Taskforce, said: “This was the culmination of many weeks planning and intelligence gathering.
“We were able to carry out the warrant thanks to intelligence received from the public, which is why it’s so important people tell us about things that are going on in their neighbourhoods. We are able to build bigger pictures off those small crumbs to put these sort of jobs together.
"With the support of the public we can continue to tackle car crime and shut down chop shops.”
What can you do to make sure you're buying a car from a legitimate buyer?
• Check the car’s history if you're buying off someone from the internet and make sure it matches up
• Check vehicle identification number (VIN) points on the car – which can be found by Googling the model
• Check the mileage matches
• Get an independent company to check the car out
• If you suspect illegal activity, tell us. Message us on Live Chat through our website or call 101. Or stay anonymous by calling Crimestoppers on 0800 555111; you won’t be asked your name and calls cannot be traced.