I can leave mine loose in the car as long as there is more than one -the only time I've had damage (which included seat belts!) is when one's been left on their own. I would never leave the car running though and I always leave it in gear (I don't have internal locking either).
Oh they have this on like everything you can think of! They have it on mugs, tote bags, shirts, baby onsies! Everything. Haha. I just went with a shirt 🙂
lol… Jill, my dog has destroyed TWO talk to me treat balls. I still love them though, they do last at least a few months. My guy has figured out how to get the recorder out though - and how to chew it to bits.