XM and General Motors have inked a deal to offer free satellite radio service in GM Certified Used Vehicles, Cadillac Certified Pre-Owned Vehicles, and Hummer Certified Pre-Owned Vehicles.

All GM Certified Used Vehicles (which includes Chevys, Pontiacs, etc), as well as Cadillac and Hummer Certified Pre-Owned Vehicles equipped with XM Radio will be available with a 3-month trial of XM service and a waived activation fee. You can find a list of Chevrolet, Pontiac, Buick, GMC, Oldsmobile, Cadillac and Hummer vehicles with XM factory-installed here.

GM is the nation's largest automaker and the industry leader in manufacturer-certified used vehicle sales, representing nearly one-third of the volume of all certified used vehicles sold in the States.

Now with this deal, XM will be available in more than 115,000 of these certified GM vehicles in 2007, and grow to more than 168,000 vehicles in 2008.