Excessive Tire noise -

2002 Ford Taurus/295k miles
Excessive tire noise in the rear of car.

Root cause. the tires were mounted in reverse direction.

I hate tires that are one-directional. When rotating you have to have at least two remounted to work correctly for the side-to-side switch.

Tires like that need rotation more often. If you neglect frequent rotaion they will build up a tapered tread that you can't overcome no matter how you rotate them.