My motorhome is almost 12 years old now and the stereo in it had a cassette deck! So I was wandering around Best Buy and found a JVC stereo system there with Apple Car Play. The stereo comes with a good size touch screen. What Apple Car Play does is allow you to control your iPhone from the touch screen.
So I bought on of these and had it installed in the RV. So now I get my iPhone GPS right on a built in, in-dash screen that is very easy to reach from the drivers seat and I don't have to use suction cups to mount it to anything. Just plug in the iPhone and I have the GPS on the screen as well as a bunch of other iPhone stuff like iHeart radio and you can see incoming calls and text messages and a bunch of other stuff. I haven't got to use it a lot yet, but from the little playing I did with it, it seemed to work just great.