Can I find a Ford Mustang navigation system for my 2005 Mustang?

I'd check ebay or craigslist. Im sure a Ford dealer could get you one, but they'd charge a lot. It might be a problem installing it if your car didn't come with one from the factory, because the Nav unit uses a different wiring harness. I would just go with an aftermarket one. The Ford navi doesn't have a whole lot of adjustments or options on it and really doesn't sound that good. I have a Alpine IVA-W505 in my '08 GT and I really like it. 7" screen, 24 bit DAT's, USB for MP3 player, full speed Ipod connection, Audyssey compatibility, Bluetooth hands free, bluetooth music streaming, and a lot more. With the adapter kit, it almost looks factory too. If you have your heat set on the Ford Nav, go on some mustang forums and search for Nav conversion or something like that, I'm sure somebody has tried or has done it.