geez4 said:So I got a box put in by a third party. I tossed up between the Mr12v and going with their brand that was "tested".
My missos Samsung S21, doesnt work (could be her car, didnt work recently in a hire car) and I can connect, but only wired, it has no wireless android auto option. So question re the Mr12v, does that work in legit, proper, wireless Android Auto, or is it plug in only?
Yes Mr12volt does work wirelessly for both CarPlay and Android Auto, as long as the phone supports it, or in some cases the phone 'may' need "wireless Android Auto" activating, but I'm sure the S21 was one that should have had it from the start so this shouldn't be the issue.
Some older mmi boxes never had the wireless option and some only have wireless CarPlay for iPhones, and this is the same for factory headunits from some car manufacturers.
Now I will state what I say to everyone I've installed for....
While you are driving and wirelessly streaming music to the unit you are using battery power at a much greater rate than normal, so this is why I don't use this facility, as I'd prefer my phone to be charged. Now you can say "well plug it in and keep it charged", yes a great idea, so in that case why not just use the cable that comes with the MMI box! Although the MMI box wont really put all that much charge into the phone (ie; if it's almost dead to start with then it still will be at the end) but it'll keep it topped up.

I've fitted a desk charger (chopped to fit flat) in my centre console, it's fixed in place so I can just slot my phone in there as I drive. This is connected to the MMI box via the USB cable.
