Whatever the new M5 has or will not have, it will look same as other 5 series. It will also be too tall and too heavy to be anything but a fast taxi cab.

At least Porsche came up with a actual sports sedan when they created the Panamera. Its just ugly as hell. It might not be light either, but its not the aerodynamic barn door that a 5 series is and its roll center is likely at least 200mm lower.

But both the Panamera and any M5 seem like a colossally bad way to spend money. They just arent worth the price they ask for them.