I'm told by my service advisor that the only reliable AMGs are the ones with the M113 engines. The M112 (V6) and M113 (V8) engines are some of the most reliable engine generations for Mercedes Benz provided they are well maintained. There is an E55 AMG 2003 model year (211 chassis with the M113K engine) that has been maintained at the dealership my car is serviced at to over 650,000 + kilometers. It's regarded as one highest mileage examples in the world of the M113K engine. Supposedly, it's on the original engine and the original transmission! The 6.2 liter V8 AMG-bespoke engine that came out in 2007 was supposedly a horrid engine with multitudes of small problems and several large problems too. The 5.4 liter Twin Turbo V8s were a lot better, but still had some other issues. So, I've been told that I should just stick with my M113K engine car. There is a 2005/2006 C55 AMG with the M113 engine (not supercharged) and also without air suspension. Supposedly that is the most reliable AMG car as very little goes wrong. BUT, since it's got 100+ less horsepower it's not quite as fast as the E55. Hardly a problem in USA since we can't go very fast in USA anyways (in California, the speed limit is about 112 KPH). But in USA, we like the bigger cars.