You know, hindsight is 20/20. I have no real problems with the box truck exterior looking like a box truck. Just like I don't have any problems with realizing the exterior of the Haunted Mansion's stretch rooms are full of pulleys and cables and (at Disneyland) massive elevator mechanisms.
But...
They probably should have disguised the box truck better. Give it a quickie decal treatment that makes it look inoccuous instead of suspicious.
I'm reminded of that scene in
Close Encounters Of The Third Kind when the US government moved all that equipment to Devil's Tower before the aliens got there. They disguised all the secret government trucks as belonging to Baskin-Robbins and Piggly Wiggly and McDonald's, etc. to not panic the locals.