Comcast (NSDQ: CMCSA) is buying out multiplatform and online car site Vehix, for an undisclosed amount. Comcast’s ad sales unit Comcast Spotlight already had a minority stake in the service, and will now fully own it.

Comcast is buying the service from an investor group led by Utah-based Ken Garff Automotive Group, which controlled a reported 51 percent stake. It was started in 1996 by car dealer owner Garff Enterprises as AutoMallUSA.com, and after changing its name in 1999, then moved into broadband and on-demand platforms of Comcast Spotlight, plus TV spots on cable systems.

As to the rationale for the deal, pretty simple: “Vehix will enable our sales teams to partner with automotive advertisers of all sizes and create uniquely efficient and effective on-air, online and on-demand marketing campaigns.” Interesting to see that no mention of Comcast Interactive Media, the online media group within Comcast….would suppose there would have to be some development and promotional overlap, if nothing else.

The site shares its ad revenues with Comcast, Time Warner (NYSE: TWX) Cable, Charter Communications (NSDQ: CHTR), Bresnan Communications, CableOne and Mediacom Communications. Some more history of the service in this MCN story and the release.