I didn't mount stock radio buttons anywhere - the module is too large to fit anywhere without taking too much room.
I used the long 50 pin ribbon cable that is listed in the parts list (https://www.northamericanmotoring.co...ml#post4483538).
It is connected to the factory stereo inside the dash. The other end is routed to lower center console (where the USB and AUX ports are).
Whenever I need to change something on factory radio I can connect the control panel there. I am thinking about routing ribbon cable to a glove compartment, but haven't decided yet.
So far I only needed to do this after disconnecting/reconnecting battery to set radio to AUX input and reset its clock.

 

I've been using CarPlay enabled stereo in the factory speedo for more than a year now (see my posts above) and everything worked great, up until recently.
Suddenly I started experiencing occasional hiccups during music or books playback in CarPlay. They were infrequent and very short initially so I ignored them, but lately became a real inconvenience.
The sound would cut out for a longer periods, additionally my navigation screen would not refresh properly and touches would not register.
There were no sound cutoffs in the radio and bluetooth modes however, so it led me to believe there was something wrong with my USB connection.
Reading online about similar symptom with CarPlay - most people narrowed it down to the use of cheap USB cables.
Since I have Apple USB to lightning cable going from the radio to the phone, that left only extension between radio and screen I have added using cables ordered from eBay (1.25mm 4-Pin Pitch JST PicoBlade Male to Female 4P connector).
I took one of the high speed shielded USB cables I found among my spare cables, cut off connectors on both sides and soldered it instead of using chain of prefabricated cables from eBay - not a single hiccup since! Everything works as expected.

Just figured I'd post this to save someone else time and trouble if they decide to go with similar setup.

 

Would you recommend the use of this dual/pioneer head unit in place of a Chinese head unit nowadays”?

Can the aftermarket radio be used directly instead of conecting through aux to the stock radios?

thanks from the future

 

It all depends on your personal preference I guess. Six years ago, when I was after CarPlay integration, I didn't like the look of aftermarket plug-and-play units. That was the main reason I went all in for the aftermarket-radio-in-original-MINI-speedo solution. This particular DUAL unit was the best compromise I found at that time which satisfied all my requirements (size being the most problematic one). Would I recommend this specific unit today? Probably not. Considering DUAL is not making those any more as far as I know. It was almost "state of the art" back then, but by today's standards it is far from it. Offering only wired connection is the main shortcoming.
If I was looking for a solution today I would do a research - three are several interesting solutions out there, including single DIN units and others. Not sure which would be better fit for R56 though.
As for aftermarket-radio-via-AUX vs radio that can be connected directly - again, it's a matter of taste and limitations that you have. Besides not being a fan of units offered at that time, my R56 had Harman Kardon stereo, which is not that easy to hook up to. I didn't want any additional troubles and wanted to keep it, hence AUX solution.

 

No experience with this unit, but I installed one of the Hualingan HL-8835 head units and it's absolutely great. There's a few threads on it.

Only complaints: it's a bit slow to boot up and connect, the warning lights could be brighter, and it takes some tweaking and know-how to get all the software working the way you want it. But none of those are showstoppers, and ffor the price it's a huge upgrade to the car. I wanted my wife to have CarPlay for nav and she's super happy with it.