How about a randomizer function in sandbox mode that picks the year, body, engine placement, and suspension for you? After you’ve clicked random, you can either move forward or click again.
Hmm, why?
for when you’re creativity is just gone
You can only play this game for so long before you find yourself in a rut. So a randomizer might be a good kick in the pants.
How many times is that? I catch my self thinking of new ides for designs everyday and I am totally still addicted.
Reset the scenarios. Start over. Find new ways to use fixtures. I really don’t see how you can run out of ideas. If you are just burned out, take a break from the game for a bit. These are the things I do.
If you really just need something “outside of your own box”, pick a real-world company and attempt to replicated it. Start a new company and build only pickups or city cars (or some type of car you just really don’t like much). Plenty to do in Automation without a randomizer. 
Go on Origin and download the Starwars Battlefront Beta; that’ll keep you occupied for a while! 
I’d much rather a car body randomizer myself!
All that dragging of the model shape is really just changing a set of numbers, how about a randomized set of those values and bam, new body shape. It can be just a starting point, you can still adhust it yourself.
For a randomizer to actually produce a feasible, realistic car, a lot of artificial intelligence is needed. This will add a lot of development time (as well as many, many lines of code; making the game more difficult to debug) for something gimmicky. I have a degree in computer engineering myself (working on a master’s degree now), so I know it’s a tougher task than it initially may seem like.