I am an RV Transporter and I own a Crew Cab Sleeper.
Federal Motor Carrier Safety Administration Part 393.76 controls sleeper berths. here's a link so you can read it yourself:
Each state is required to mnake their state statues conform to the FMCSA regs and they do. The problem comes in with the enforcement of the statues because every state, and in many cases, every officer, makes his own interpretation of the reg or statue. The State of Indiana Commercial Vehicle Enforcement section of the State Police has determined that the crew cab sleeper does not match the reg in that the window insert does not provide the necessary height. That is their only objection (and possible violation) to the CCS.When you use the window insert to assure that you reach the required 75" length of the bunk, then you fail.
But that's Indiana. Iowa has two primary enforcement units for commercial vehicles the first being the State Police and the second is the Iowa DOT commercial vehicle enforcement folks. The State Police say the CCS matches the statue and is acceptable and the Iowa DOT says it does not,
In my state, Illinois, the State Police and the Illinois Commerce Commisiion (they run the scales and enforce the FMCSA portion of the state statue) both say that the CCS is acceptable.
The bottom line is you spin the wheel and take your chances because the human angle is too unperdictable.
So what I do is not log sleeper berth time. I log off duty. If a cop asks me what I was doing during my off duty time I just tell him that I wasn't in, around or on my truck. I don't have to prove myself innocent, he has to prove me guilty. If he doesn't have any evidence that I slept in my truck (and I am not going to him any by admitting that I did) he cannot prove his case.
That isn't going to stop him from taking me out of service and issuing me a ticket but I will make him look like a fool in court and then sue him for false arrest.
This all comes down to money. Just about every state is in desperate need of revenue and any citations that they issue keep the bucks coming in. There is also the problem with cop egos and their need to appear to be productive.
Before anyone fires on me for bad mouthing cops, please note thatI have retired three times. One of those jobs was as a police chief after 20 years service.