Let me start off with....sorry this is a long one. I have ran out of options. This all started with the fact that I needed new Axles and had a bad driver's front wheel stud. never done a wheel stud before. I changed the wheel stud by taking the brake caliper and disc off. Then I cut the bad one in half with an angle grinder....popping it out and putting a new one in that I ground down an edge and froze over night. It went in nice....but I did hammer it while spinning a nut to make the stud seat completely. Didn't seem to be a big deal. Put a new axle in on both sides (O'Reilly-Kragen brand new axles). Then I went to the rear and put a brand new Benen lower tie bar on with the new bolts I had to buy for the extra thickness of the Benen bar. So I test drove it and felt a vibration under acceleration at lower rpm's (like 1800-3000 mostly). Felt like the driver's side more than anything. It reminded me of a shimmy you get with bad shacks on a launch....just much less intense. Almost an up/down motion...but this is just my best assessment. I jacked it up and checked for play in the wheel. Nothing. Then I checked the bolts that I remember tightening well in the first place....no problems (was hoping it was just a loose nut!). I got under it and looked at where the driver's axle connects to the half-shaft. It was out about a 1/4" (maybe less) but I slide it and it seated in but I could also slide it back out a 1/4" pretty easy too. I then checked it from the top when the wheels were on the ground and it didn't move at all. Passenger side didn't move at all. I don't know if this is normal and I have never had a problem when I have put axles in (done it on my hatch 4 times). No vibrations or anything. So I never checked for play in the axles. I googled around and my car's symptoms seems to usually be a loose bolt or bad axles. But my bolts have been checked and my axles are brand new. I also took a pry bar to the various suspension parts and don't feel any play there either. I do have old KYB shocks but have rolled on really bad shocks before. I think I would hear some noise if the wheel hub bearing was bad from my hammering on the wheel stud (3 friends have thought the same). My alignment....wasn't sure but I talked to a tech at a alignment shop and he doesn't think its that. It can't be the new lower tie bar??? I googled it and found no threads related to the rear lower tie bar. I am tempted to take it off but I kinda feel stupid thinking its the problem. maybe get a new axle from O'Rielly?? ANY OTHER IDEAS???