I rarely write bad reviews; usually I just don't recommend a place that is mediocre or poor. In this case, though, I believe that Firestone was deliberately trying to fabricate a problem, so that's serious enough to share.
My husband took our car (it's an old one, a 1986 Chevrolet Cavalier) in for an oil change. The Firestone guys were very nice. They called him in to the repair/service bay, where the car was on the lift, and showed him a trail of oil coming down through the engine. They said that we needed about $500 worth of repairs for the leak.
We were upset and worried about how we were going to pay for this repair, so just for hope's sake we took it to another place for a second opinion. The second place examined the car thoroughly and said that we didn't have any leaks at all.
That was eight months ago. The car's still driving fine; no leaks on the parking lot. I think that's pretty definitive: Firestone lied to us to get our money.