Here’s an alternative for your set up as opposed to drilling holes for a usb port.If you are going in the bush, you need more than one way to navigate. Garmin GPSs are super reliable. Phones are often dependent on having a cell signal and can have battery or heat issues. I've been on trips where the GPS quit working (cord issue) and a different trip where I couldn't get the phone/app/carplay combination to function properly. I like to use my Iphone with the GAIA app displaying on the radio's big screen through Carplay. I also run a Garmin 276Cx at the same time. One of downsides to the phone app is that the pointer occasionaly freezes up. Another is that if I get out of my Jeep with the phone to take a photo, getting the phone, carplay, and the app to work together when I get back to the Jeep can be an issue. Another is getting my phone to make movies while he mapping app runs in the background (using the USB in my 2020 Jeep so I could use carplay to display a map would block the mic on movies I made with my phone. Using a bluetooth device for a wireless connection solved the volume problem but makes the start setup more ocmplicated) . The problem with the GPS is older maps and slower processing (especially processing with the 276Cx). One advantage of having 2 forms of navigation is that I can have one device zoomed in to see the turtns better and the other zoomed out to follow progress along a route.
BTW, I've been thinking about dashtop power for my devices for years. I just can't bring myself to make holes in the dash.
