AutoBuyGuide.com gives you all the details of each 2006 GMC Sierra incentive program from the manufacturer and dealers. You may be throwing away thousands of dollars if you're not taking advantage of current incentive offerings! Popular 2006 GMC Sierra incentives used to entice new car buyers are interest-free auto loans. GMC and its car dealers will utilize these cash, lease, and finance 2006 GMC Sierra incentives to lure consumers to buy specific vehicles that they may have overstocked or to help clear out last year’s models. Occasionally, they will run factory-to-dealer GMC Sierra cash incentives to encourage car sales.