How to install an amp and sub in a 1999 mercury sable ls?

I just bought a 1999 mercury sable ls. here's what im looking to do with it : Install a subwoofer or two, an amplifier, cables, and anything else needed for the installation. the only problem is im keeping the stock head unit because my climate controls are electronic so icant change the unit. im just stuck on how to even go about installing this with a factory unit. please let me know anything and everything possible you know on how to install subwoofers and an amps ina car with a stock stereo. Here is what the head unit looks like to show you why it cant be replaced : http://carphotos.cardomain.com/ride_images/2/4420/3741/23549370010_large.jpg|||If I were you, I'd consider dumping the electronic control head for the standard one, then you can use an integration kit to install a much better head unit.





...|||Best way to get the signal from the factory head is to tap into two of the speakers with an amp that can take line level inputs. Once the amp is wired, then the rest is basics. Now - A second approach.... Nose around %26amp; see if there was a factory sub available in that year. IF there was one, then the factory wiring is still there, buried under the carpet or such. You could try e-bay for a used factory unit %26amp; just plug it in, or see if you can get a cleaner signal out of the factory plug. I got a used factory sub for my Grand Marquis %26amp; it fit into the factory stock location quite nicely... While you're looking, maybe see if there was a factory trunk-mounted six CD changer available, also. Again, the wiring is there, somewhere.

Also, check CrutchField.com .. because I do think there is an aftermarket head unit specially designed for the oval hole.