I have the USA SPEC HON product. It hooked into your oem HU and allows for either an iPhone connection or RCA so you can put an headphone jack to RCA plug. Oem HU has full functions including Cd changer and XM. My problem was that in less than a year the supplied iPhone connector shorted and so did the XM wire. The company replaced the iPhone wire but once the XM wire broke I said forget this. I since installed an aftermarket radio with USB, headphone in and Bluetooth and the sound with the stock speakers is greatly improved. I wanted to keep everything oem but that's a mistake. You should definitely get an aftermarket head unit and not waste your money. You'll have to do the same exact amount of work to put a hookup in the oem as you would to replace the oem HU. I wasted time and money doing what you want to do. Just cut to the chase and get a good aftermarket HU.