I once had a friend who was a Zoologist. She took a year off and went to help out a brother in Arizona and asked me to watch her car. She had mold all over the place, dead plants and even had a little 'garden' with rocks, bones and even a small animal skull on the dash. I was tempted to wash it but thought it would make her mad. I did inherit two coolers, a small one and a larger one. Later she told me it's a good thing I did not know what those coolers had once contained.

Not a good idea.
Weeding while in Wheeling is more distracting than Texting through Texas.

I WFH, my car is spending M-F parked in my darkish garage. Most weeks I only drive on the weekends. I can't see that as working out well for me or for the plants.

Bloody mad. Just more to injure you in road accident.

Judge "Why did you let go of the wheel?"
Driver charged with dangerous driving "the cabbage growing on the backseat bounced off the windscreen & hit me in the face"
Judge " Is that why you lost your eyeball?"
Driver "no sir, that was the spiky cactus growing in the eye level air vent, puncturing & rupturing my eyeball!"

I have lost succulents inside my car - as summer can get very hot.
Very cute idea, but I'm not risking my little guys.