Mystery S class

[artypossum]

Today I was walking along a street and I saw what I thought was a Mercedes S600 (because of the two fat exhaust pipes) but apperntly it wasnt: It had an S500 Badge( maybe S600 because I wasn't wearing my glasses) and on the other side (where the AMG badge would be) was a badge that read 4MATIC. It had two fat exhaust pipes and a really nice front spoiler. Does anyone know what it could be?