I agree with Roger. If you are certain it was Firestone at the very least
you should bring the issue to their attention. It doesn't have to be a
negative. I've had "complaints" from clients before that were less
complaints and just FYI's - I've used those small issues to improve our
service (completely unrelated field but the idea is the same).

Besides - like someone else emntione it can be dangerous. I had a friend who
took his car to one of these quick oil change places and they put the wrong
type of fluid in his brake fluid resivoir while topping it up for him.
Whatever they put in disintigrated every peice of rubber in his brake system
- luckily his brakes failed at a "non-crucial" moment of driving. To their
credit that shop owned up and insurance covered the repair.

--
Thanks,

Jeff
'90 Carat (Grover)
'86 (We call this one Parts)
'78 Bus (Melissa) Patty's Bus