The National Highway Traffic Safety Administration (NHTSA) is investigating certain GM vehicles after receiving twelve complaints of smoke and fire from the inside of doors of some Trail Blazer mid-size sport utility vehicles. The complaints are similar to consumer reports that lead the NHTSA to open an investigation into some 2007 Camry, Camry Solara and Rav4 vehicles, earlier this month. The NHTSA will be focusing on whether window switches on the GM and Toyota vehicles were manufactured by the same supplier. The investigation could affect up to 310,000, 2006-2007 Chevrolet Trailblazers. According to the safety administration, the Buick Rainer, Saab 9-7x, and the GMC Envoy share the same parts at the Trail Blazer, but these vehicle are not part of the investigation yet