Mercedes just announced their new C63 will be a 4 cylinder hybrid platform, and they have released information about their electrified "73" platform. These utilize a rear limited slip differential with a integral motor with 2 speed transmission.
This is quite a departure from the 53 platform M256 E30 . Which utilized an integral starter generator behind the engine between the engine and transmission. These hybrids are more of an addition to traditional ICE engines such as the M177 platform.