G-Max tires
 

Let’s say someone rotated their tires side to side and just learned the rotation direction is backward, what does that do to the tire and car?

It'll drive kinda of crappy, as the directional tread groves won't work like they are deigned to do, especially on a wet rainy road. Also on a dry road you will loose some traction because of the incorrect direction. Won't hurt the car, but the ride safety will be affected.

I do not know if it is correct or not but I have been told after some miles of the tires going the wrong direction than what the tire is supposed to the steel belts in the tire will come loose in the tire itself and ruin it. As far as the amount of miles it takes to do that I do not know. If it was mine I would get them all going in the right direction soon. Like pretty quick!

:facepalm: :facepalm: :facepalm:

The steel belt doesn't care what direction the tire tread are turning...

My first guess might be excessive tread wear plus the grip issues mentioned above

Maybe some hydroplaning if you are going too fast anyway in water.
Slight extra noise. I've had them mis mounted and the sky didn't fall. I wouldn't worry about it until next rotation. Unless you're the type that haulsass in heavy rains.

If your talking about the tires on your Zl1 you shouldn't rotate them if they have directional tires. Probably not the end of the world, but I imagine handling will suffer. If a tire shop did it, even if you asked them to they should have caught it and refused. its such an easy fix I would correct it to avoid any problems. If a tire shop did it they should be willing to do it no charge since they are the "experts" and should have caught it.

Well you were so quick to correct me and since you seem to be an expert on tires why did you not answer the OP's question?