Solo44

I recently acquired a 2010 IS250C with navigation radio. The radio screen is about impossible to read in the daytime with the top down - partly because the previous owner wore the screen surface pretty bad, and that type of screen is very hard to read anyway if you're wearing polarized sunglasses. So, I'm looking at solutions. One option is to replace just the touch screen digitizer with a new one and that would improve things a bit, but it will still be hard to read with the polarized glasses. The second option would be to just replace the factory radio/navigation unit. I've seen the video for the unit sold by 4X4, but it's not clear to me whether that unit actually includes a real GPS, or if it requires you to use something like Google Maps accessed from your smart phone. I also saw another offering that retains the original nav screen, but allows you to add a new radio with screen below the factory screen. With that approach, it was unclear as to whether I could use the factory GPS antenna and backup camera. So, am looking for advice on a good approach that results in having a real GPS unit that doesn't require a smart phone, and retains all the original factory functions such as steering wheel controls, and backup camera.