Try outside King county. I wouldn't want to drive one in Redmond or Bellevue unless I'm headed out of town and never come back. The cops will absolutely pull you over.
Not sure where you are coming from with this to be honest. I had my LMTV all over Seattle, Bellevue, Redmond, etc when I was living in Redmond, and no cop ever cared. In fact no cop has ever cared about it anywhere, parked, moving, or broken down. Except one time I ever had a cop interaction was in sedro wooley of all places... and she just stopped when I was standing outside it waiting for a friend to tell me it was really cool. I've driven it through capital hill, montlake, fremont, downtown, you name it.
On the FMVSS issue if that is jamming up WA registrations now, besides that court ruling that seemed to find the exemption transferred to private ownership, the FMTV was built to FMVSS, as specified in the contract. This actually caused S&S some hassle as the original vehicles arguably didn't comply and the gov't went back on them to get them to pay to fix, ended up in court. This has come up before, and I've run into it in non-army truck situations too, and the consensus seems to be to just slap a FMVSS sticker on the door jam if the equipment actually is legal. We even had at least one thread about it:
https://www.steelsoldiers.com/showthread.php?149479-DMV-asked-for-FMVSS-proof
For whatever it's worth, not much to you WA folks, Arizona didn't even blink, couldn't have cared less. I just said it was a cargo truck and their magical system that she said had every VIN of every thing ever made took the serial # as the vin without hesitation and spit out a title. Insurance on the other hand...