As mentioned in an earlier post, I had two concerns about this kit: any decent racing team will include two or more cars, and have a team of more than two people. The crew cab fixes the second problem.
To allow for a second car, the upper car deck structure has been roughed out, using the spare tire rack from the kit.
As I have chosen to keep the wheelbase intact, the extra length of the crew cab will require shortening the vertical lockers behind the cab. The upper deck will be supported by a structure within what is left of the vertical lockers, and by beams reaching down to the front bumper either side of the hood.
The pictures show that my paper plan was pretty close but that the upper deck needs to be raised slightly. This is because the cab sits higher on the chassis than I had assumed. This does not seem to be related to any mistakes on my part in assembling the cab and interior, or the cab mounts to the chassis. Nonetheless there seems to be a lot of space showing between the cab floor and the chassis rails.
The drawing also shows a potential approach to tilting the upper platform for getting the car on and off the upper deck. This is still undecided. Stay tuned!