Back in the Brass Era, 1914-1916 or so, GMC offered electric trucks for drayage. Random E Olds was experimenting with electric cars as well. But that may have been before it was part of GM. GM is probably the only modern manufacturer that can claim to have made electrics way back then. I don't think MB did. Ferdinand Porsche made a few - but that was 40 years before his son Ferry started the current Porsche company. So any link there is tenuous.