Probably the best thing to do here is to get the car up in the air and start by visually inspecting the steering links, struts, wheels, wheel wells. If nothing jumps up and grabs you, start shaking things up, sometimes a good shake will reveal the culprit. I've even resulted to hammering on stuff with a rubber mallet, although I wouldn't advise that unless you know what you're hammering on. Last result grab a wrench and start checking fastner torques.
Finding this kinda stuff can sometimes drive ya half looney and sometimes it jumps up right before your eyes !!!

Good Luck