The Mercedes-Benz Extended Warranty is a third party offering itself - it's marketed by Mercedes but is provided by Allianz Assist. It's a good package, though. Indeed, it's about as comprehensive as an aftermarket warranty can be. We'd suggest looking around and comparing the extended warranty market before committing as other providers may offer a better deal, but the Mercedes one is definitely well-rated. Do also check out Warranty Direct, Warrantywise and Motor Easy and make sure you read the terms and conditions carefully.