Google works with a number of partners to get the vehicle inventory. Dealerships can select their primary and secondary inventory providers directly on Google or turn off the vehicle listings:
Follow the steps at Manage vehicle listings on the Business Profile.
Make adjustments to your preferred providers or turn off your vehicle listings. If you don't set a preferred provider, Google chooses a provider based on the overall data quality, such as the number of high-quality vehicles based on data completeness (photos, options, VDP, etc.) and data freshness.