I recently bought a really cheap Android Auto screen for my car. It had a USB-C power input. Suspicious, I opened up the supplied cigarette power adapter. The USB power pins were hooked straight to the car battery rail. On most vehicles that's connected straight back to the alternator. Hilarious. I wonder how many people fried their phones because they thought "oh, I forgot my charging cable, but I can borrow my nav screen's for a bit"...