My friend was at impressed with the factory radio that came with his car, but rather than replace it, he got another one. They are all functioning but he prefers the replacement. Is there anything he'd have done to improve the factory radio?
Most times people decide to get a different radio because the factory radio cannot be modified or lacks such functionalities like the USB port. I have both radios on but I never use the factory radio. Seems a bit cumbersome to operate both, if you ask me.
I can understand why you would want to replace the factory one but I don't know why you would keep both, especially since it sounds like it's not really used when there's another option. What's the reasoning behind it?
I agree with the rest of you. I'm not sure why you would need two radios in your car. As for the original question, I've read about some upgrade systems that are available for factory radios. I've never tried one myself, so I can't say how well they work, but you can read about them here. These might have helped out your friend, depending on what it was he didn't like.