3.5mm Aux Cable Retractable Black [Electronics]
Mine came in a day ago, and so far it works fine in my car.  But, if you have an iPhone 4 with the apple bumper case, you have to stretch the opening of the case around the headphone jack a bit to get it to plug in properly.  Not a horrible problem, but something to consider if you want to be able to plug your phone in quickly without paying much attention to it.    I wasn't blown away by the sound quality, but for what I paid, I'm satisfied.    Overall, what I got was what I expected.