When making full turns, going slowly from stopped position. Car has vibration and rumbling. This occurs in either direction. Example pulling in or out of a parking space. I was told that it could be the tires. Anything more than that? It is a 2005 Subaru Forester auto transmission and no other problems, that I am aware of.
Judging from your post you MAY have a worn wheel bearing.
This could also be a case of a failing viscous coupler.
Has the car ever been run with mis-matched tires?
Has the car ever been run with the donut spare in place without the FWD fuse being inserted, as per the Owner’s Manual?
It could be just the power steering pump kicking back from you holding the wheel so far left or right that you are trying to force the steering past the bump stops. Once you get the steering wheel as far as it goes release the pressure on it and see if that helps.
My 2004 Forested had this problem. It seems to have been cured with a transmission/transfer case fluid change.