My 2018 takes foerever to charge my iphone no matter what i am using as a source, usb, apple car play or,wireless charging. Have others experienced this as well? My 2016 s63 charged my phone much faster. Also, does anyone know how to activate the standard 12 volt plug in the rear? When i plug something in mine puts out no power and the light next to the plug is off.

I noticed that, too.

Must be a low amp situation. The wireless option definitely is.

I was guessing that, and the fact that I usually have multiple apps open - 2-3 map systems running, and sometimes streaming music.

I think if you lock the phone it will help a bit - otherwise I think it the screen stays on (lit) if you have car play running.