My '08 Cobalt has had a front end 'knock' noise, both sides, since mileage in the 15K range. Dealership could never find it...did the sway bar bushings, control arm bushings--did nothing to alleviate the noise. In fact, they even replaced the column which to me was never the source of the noise. Less than twelve months after the comped column replacement, the 'new' column was rattling! Took it back; they first replaced the power steering motor free, stating that's where they thought the noise was coming from. I returned as the column noise was progressively becoming worse; they then comped the second column for me. That last one didn't last twelve months! WTF?? Now I have a rubbing noise in the column when I turn at low speeds (parking lots, driveways, etc.) and they think it's a plastic ring part in the column...about $300 to replace. I don't suppose their being in the steering column twice in the past two months (replacing column and power steering motor) would have anything to do with the noise, would it? Sheesh! I have owned 13 new Chevrolets since 1981 but this one is making me re-think my loyalty. My daughter's PT Cruiser, built within one month of my car and with mileage 1K less than mine, is completely silent over bumps in the front end and the steering makes no noise whatsoever. If Chrysler could do it, why not GM?