I met a guy up in Ludington, MI this past week who had a 2011 BC (around 38-40') with a very nice 2" receiver setup installed by his dealer. He said it was a standard reese hitch. He was not double towing, but the hitch was clearly adequate to do so. He was using it for a large bike rack.
MI has 65' double tow restriction and a "R" endorsement required for your license, which stands for "Recreational Double". There is a 20 question test and a small fee, of course, to obtain the endorsement.
I'm pulling a 38' BH with a long bed, crew cab dually, but would love to get a hitch to pull our pair of jetskis, just twice a year for a short distance. 95% freeway. I've spoken to many law enforcement officers who are not even aware the "R" endorsement exists, much less, the knowledge of a length limitation. So getting pulled over is highly unlikely, at least according to the people I've spoke to. By my calculations I'd only be at 67' anyway, so marginally close to the limit in any case.