The current Mercedes-Benz AMG saw it’s first daylight at the Frankfurt Motorshow in 2005 and was brought on the market early 2006. Being 2 years in the showrooms seems to be a sign for the guys from Stuttgart to refresh the looks of the über Benz. Spy photographers have caught the S-Class AMG facelift on the road in the American desert performing hot weather testing. Offcourse together with the regular S-class, the AMG version will undergo a refresh by getting a new and lower front bumper. It also looks like a set of new exhaust tips may be in the works since this prototype is sporting generic exhaust pipes. The S63 and S65 AMG models should keep their current powertrains, but may receive a few technology updates. The S-Class facelift is due for unveiling in 2009.