Some set photos from Dubrovnik showing costumes and what looks to be a speeder:
http://www.starwarsnewsnet.com/2016/03/first-look-at-troopers-from-the-starwars-episodeviii-set-in-dubrovnik.html
The aurebesh on the guards’ helmets says “CBPD”. I’m seeing some people suggesting that it could be Han’s funeral procession, but that sounds like nothing more than wild speculation to me. In any case, someone on reddit pointed out that the guards seem to be pretty clearly based on this McQuarrie design:
