mudguard:
To be fair I don't have an issue with a tow bar on anything really. If I had an M5 I'd rather have a towbar on it than have to have another SUV/Ute just to tow stuff.
Besides, some M5s have a stonking great V10 in them. Surely they'd be great for towing!
or at least the diesels. My A4 is a 3l TDI, it has a tow bar. As mentioned above its a manually removable one.