It should come abart at this point.the bumper and the interior and the chassis all have tabs that kinda stack in the rear. Wiggle the chassis and pull forward, it should come out. And if you are working on promos , you need this polish.
I know this car didn't exist, but I used to read Car'toons , and all those great looking rides those guys would draw. My builds are really just cartoons. Probably wouldn't work .