When I was younger, I spent years in a big rig truck. I can tell you that they are NOT 6 tiles wide. More like 5 with the bed going all the way across the 3 tiles in the back with the trunk under the same three tiles and not nearly enough room to use up a whole tile separating the cab from the bedroom.
Also, the two trunk tiles in front of the rear tiles should instead occupy the same tiles as the bed. I’m going to try to diagram this out, but it’s been a long day so feel free to ask questions if something doesn’t look right.
Panel-panel-panel-panel-pane Tire-panel-engine stuff-panel-tire Mirror - windshield - Mirror Door-seat-aisle-seat-door Panel-box-aisle-box-panel
Other than the changes I’ve shown and mentioned, everything elses placement is accurate after the semi is modified to a 5 tile vehicle