Hear of them yes. Work, yes. Make a big difference, Depends.
If you have done everything else to your vehicle, struts, springs, sway bars, tie bar, 16 or 17" rims, race grade tires, then and only then will this make a noticable improvement.
If you haven't done all that stuff, you'll probably never notice any difference because your suspension is flexing enough that your uni-body doesn't flex.
If you MUST get one, don't waste your money retail.
Go on ebay and grab one listed for civics, as prices are cheaper.
If you go unver Cavalier/Sunfire, you'll be paying more by about $10.
Its a universal bar, you cut the middle junction double ended bolts/screw thing to fit.
-M
Remember....syringes go in the RED waste basket.
It might be helpful in an accident but not much more.
