I also Have an 06 FX35 and recently I went over a big bump and felt like I was sliding on ice for a second, really weird...then it "grabbed" and was fine again. There was no ice. After that day, whenever I go over big bumps now, it feels like I am on ice for half a second. REALLY freaky, although I am getting used to it now. BUT something changed that day when it first happened. it did not always do that! I have researched online a little bit and it keeps coming up as alignment is out (even though it seems to roll straight, it was just aligned a few months ago) or it's time for shocks/struts. We'll see I guess...