wish I'd have seen THIS thread prior to posting my question. Looks terrific.
What did you use to secure the usb plug in the opening under your head unit? Looks very nice. I'm hoping to install mine this weekend, and will post pictures upon completion.
Believe it or not, zip ties. I fed it inside the cubby hole after drilling the slots bigger and then drilled smaller holes on either side of the USB and Bass Boost knob. Then, I threaded a zip tie in one side and around the other, and zipped it tight to where the top rested flat on the cubby hole. I did it at the edge and right behind the USB end where it flattens out to the cable.
It is nice because it holds very well and you don’t have to fight with it to plug anything in. My iPhone USB cable works fine and even some SanDisk USB sticks fit without problems.
There is plenty of space behind the cubby hole, so I wrapped up the excess USB and laid it behind that.
If you have any other questions, feel free to ask!