The clunking in my car turned out to be a sway bar bushing that had failed. I have the HUGE BMR front sway bar (1 1/2"), and I wasn't able to find bushings that would fit in any of my local stores. I called BMR on Tuesday night and asked to buy a new set of bushings. They wouldn't take my money, but dropped 2 new bushings and saddles in the mail that night, and they showed up today.
That's how you do customer service!
That's how you do customer service!