For anybody looking for an easy way to add USB ports to the X1 Carbon without having to splice wires or even cut up a Bambulab bus cable then this is the solution.

Components needed -

Bambulab 6 pin bus cable - https://uk.store.bambulab.com/products/bambu-bus-cable-4pin?variant=40206175141948

USB Car charger socket - https://www.amazon.co.uk/Charger-Socket-Switch-Adaptor-Caravan/dp/B0BP7KSC3C/ref=asc_df_B0BP7KSC3C/?tag=googshopuk-21&linkCode=df0&hvadid=641811723023&hvpos=&hvnetw=g&hvrand=9709425445003907819&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1007147&hvtargid=pla-1965311653846&psc=1&mcid=0163486cbf573b80aadd1d043dfe44a6

Assuming you have ordered the exact same items in the links then its as simple as inserting the red wire from the USB sockets into the 24v pin on the BUS Cable and then the black wire into the GND pin as per the image taken from Bambulab wiki then plug the other end of the bus cable into the 6 pin port on the back of your AMS and you have added 2 USB ports to your X1C. This case can then br printed to keep everything neat and tidy

Disclaimer - I cannot guarantee the products you order will be the same so it is your own responsiblity for checking wiring diagrams and ensuring all connections are correct and as expected. I cannot be held responsible for any damage caused attempting to replicate my results and am only providing this as a guide because it worked for me.