You could import a real car model as a fixture, making an actual body to place fixtures on is a lot of work. Well, a lot more work than making a fixture.
You can look at some of the modding guides that are around here, or pay someone to do it for you.
I was thinking of somehow scanning the model, first by body and then by chassis.
Like how you can make the body invisible, then scanning that to get a rough estimate of what has to be done.
Then make the chassis invisible as it would be a shell that would be easy to scan if possible.
The chassis would be an issue as scanning isn’t well made for complex structures.
Engines can be bought from a supplier and be tuned to specifications with transmission and drivetrain.
A possible way to get the body to be made out of materials like carbon fiber, fiber glass, or aluminum would help, as I wouldn’t want to use the plastic straight from a regular 3D printer for obvious reasons.
I had seen some ads about metal 3D printers, but not sure if they can be used to make a car on par to size.
Goals that would be needed to accomplish this:
Find a way to 3D print all fixtures and body with some features being independent in the process.
Find a way to make the chassis printed(hardest part of this).
Source parts and tune them(probably the easiest part of this).
It would be enough for low res sketching but true 3d printing would have to come from something much more in-depth. Automation is many-x less polygons than true 3d cad. Of course that’s obvious when you zoom up close on the body, and watch the fixture merges. It all gets pretty ragged up close. Conversely though, if there is a sufficient cad drawing of a real car you can IMPORT it to Automation, with some tools. BradLee was toying with a mkiii Supra body and I’m just waiting for that one since that’s my favorite car ever.
I could just print the parts if given the model and then do some homemade forged carbon fiber; chop up carbon fiber, soak them in resin, then apply them onto the 3D printed part into order to mimic the shape, wait for it to dry at a temperature for curing(preferably 250°), pry it off the original part.
Carbon fiber could be applied into the part whilst being soaked in resin waiting for it to dry at temperature and pry apart in order to have a carbon fiber version of the part.