Some first-time or small dealers owning fewer than five rooftops have had trouble securing floorplan loans this year.
The seasonally adjusted annualized rate of sales in October came in at 16.18 million, the second-highest reading of the year.
Magna said third-quarter sales surged as greater microchip availability allowed for higher vehicle production globally.
AutoNation Inc. sold eight dealerships in the third quarter in a move CFO Thomas Szlosek attributed to "optimizing shareholder value."
Scout Motors' plant in South Carolina could one day build vehicles for other VW Group brands or other automakers.