I'd think dealership is the way to go. They will know your car well and be aware of issues (maybe not documented) that it may have.

I'm not a mechanic (well, I am a licensed A&P...) but I do work on all my own cars and I know not to waste time with aftermarket stuff. Especially when you're paying for the labor, the few bucks you'll save on the part are meaningless. The Firestone guys should have known this as well...

I stick with Volvo because I know all the ins and outs of them (besides safe, reliable, etc...). But, I'm sick of front wheel drive, my next car may be a BMW, but that gives me trepidation...