I know this sounds retarded... but also check to make sure all the lugs on your rims are tight.
Stupid me, I was working on my suspension, put the rims back on in a hurry to see how the ride was, and didn't tighten my front left that well.
I drove for a good 1800 miles before I decided to check my lugs!! I went from Delaware, to Kentucky, and back with a lose wheel, and raced and beat an Eclipse after driving 500 some miles on the way back!!!!