Just jumping in here to report that my new RD45 arrived within less than 3 days,
And I just couldn't wait, I installed the unit and replaced my burned out screen in the middle of the night.
Everything just worked straight away,
I now have Bluetooth, Aux, Handsfree calling (built-in with RD45) with the stock PSA hardware, both units (radio + display) came in very well packaged and protected,
And it all looks brand new, clean and shiny, and both in pristine condition, I'm very happy with this upgrade
I'm glad I bought from the UK with 6-months warranty,
It was item on eBay:
https://www.ebay.com/itm/112813449128, from this fellow:
https://www.ebay.com/usr/oem_car_audio? ... 3561.l2559
The seller pre-programmed my VIN into the unit correctly,
and even asked me about the configuration of my car for the options ( CD changer [no], Parking assist [no, I have 3rd party system installed] )
The Unit was manufactured in the Czech Rep.
I'd like to thank this forum for helping.
@KSTD22 Personally I'd recommend you would create a topic of your own,
nothing against the discussion

but my thread's title is mainly about the origin of Chinese Ali express RD45 units,
and for reaffirming that my plan for the RD4 to RD45 is a sensible decision..
Also, as other posts in the forum have stated, Diagbox options available depend on the version of diagbox, and it was recommended to use 7.57 for C5 III X7 (RD),
I'm not sure about 2007 Citroen C4 exclusive..
Edit:
also note that the colored display is quite rare I think,
in my search I have never seen it, never knew it existed, until you brought it up in this thread..
I would have wanted that for myself as well, but it felt like it is more non-standard, more unconventional, so I opted to just use the more common? Amber pixelated display
(I may be completely wrong, I honestly don't know..)