Short story: driving the Z, Heard a METAL SCRAPING METAL sound, got out looked under the car, nothing. had some tire vibration when turning left, guy at dealership said it came from driving on a under inflated tire, when the guy brought it to me. Could this be the cause of it.

 

I'm not sure how you would get a metal to metal sound with underinflated tires.
If your car has not been lowered there should be nothing hanging under the lowest point of the wheels even if they didn't have tires on the wheels.

It's a safety measure, so that if you get a flat no part of the car can drag on the ground. I'm guessing the dealer actually locked under the car to see if something was hanging. Add that service mans response to your list of other lame things they say when they don't want to deal with your car.

 

After he said that, did you look at the wheel to see if its all scraped?

 

Was the TPMS giving you a warning?
That explanation does not go over with me.
Are you still hearing it?