I have an 06 Mazdaspeed 6 Sport. I got a good deal on it, but the one thing I wanted but didn't get was navigation. I don't really want to go the Tom Tom route or try to hack up my factory stereo to install an in dash unit. Is there any chance of getting a factory unit through a dealer? Anyone know how difficult that would be to install or what parts would be required. Thanks...(drive2)