What Is This Mystery Mercedes Mule? The Next SLC? Maybe A Maybach Coupe?

The spy shooters of KGP happened upon a Mercedes mule of some sort on a car carrier out getting prepped for hot weather testing by a team of AMG engineers. They're of the belief it's an SLC mule, but the boys at the Road that's ever-Winding question whether maybe it's the long-rumored Maybach coupe. We're unsure of what it may be because really — there's not much for us to go on here — what're your thoughts on this here mystery Mule? [Winding Road]