Please see my photo folder on this forum. There are other formats by others, maybe not as long an extension but this is one permutation that works so far.
My first attempt at mobilizing a uBitx was with the original 20x2 LED screen. I extended the volume, tuning & function knob, mic of course, and the LED screen by means of a 25-wire printer cable. The Arduino/Raduino stuff remained with the mainboard in a box under the pax seat.
The current model uses a 2.8" Nextion LCD screen on a 4-wire shielded keyboard cable so I can see it at dashboard height. One could have run the rest of the controls to the same location though the screen data nose gets hard to isolate... plus, I wanted the finger controls at a convenient arm-rest position rather than at a reaching position. There's also one less microphone cable flopping around right in front of other things. The tuning/function knob etc are therefore...
...located in a separate control head that's fed with a separate, VGA monitor extension cable.
One nice thing about the latter cable is that it has four separate, shielded paths along with some extras, all shielded again by the outer layer. These can protect the audio path and stuff. I can still hear some of the Nextion activity, chiefly the data streams associated with the 2nd Nano and spectrum/s-meter action but mainly on weaker signals with the volume up.
I find the speaker audio, even with a Motorola public-safety type radio speaker, a bit mild for 70mph highway use so I'm adding a 15-watt amp to it.