I'll be able to tell you for sure in about a week 'cause that's when it's being fixed, but I think it's the sway bar bushings. My 'Corde does it, my dad's 'Trep did the same thing and that was the solution. Does yours go away if you hit the brakes hard? I found that mine will start clunking if I hit a bump, then it will keep doing it until I get the loose thing back into alignment, usually by hitting the brakes enough times or by stopping short.