First off...new to cobalt mods. After installing pedders and fe5 shocks and struts on a LS, I had a nasty clunk at low speeds. After trying different orientations of the top hat tab, no sway links, and struts in and out 6 times...I took it to a buddy's shop.
So, what did we find? Found out my compressor didn't have the ***** to put the nut on all the way
You should see a couple threads above the nut. Also, as you lower the car to the ground keep an eye on the top of the strut in the engine bay...if the nut moves up (when looking in the top hat) when the tires touch down...the nut isn't seated fully. I didnt have this issue on my Z28, so ot never even clicked that it may be the issue.
Maybe this may help somebody out.

 

The three top nut/bolts have given me problems twice. Was taking my stock ss/sc stuff off to trade with an lnf and the bolt head wouldnt grip when loosening it. I ended up cutting the bolt off and installed it in another balt minus the bolt as the car was being traded in.

On an lnf I was helping on intalling springs the owner went to tighten the nuts to specified in/lb and the bolt just snapped off. So he is also minus One top bolt/nut

 

I replace wheel and upon driving around i had the same issue. I got home, thought i was rubbing or something, saw the wheels were completely tightened down. facepalm is correct!