I forget who posted the photo below, but as I recall, the author had extended his top USB port to the rear cubby, so that there would be no phone or iPod (and USB wiring) in front of the shifter, and then put a piece of black tape over his top USB port to block access to it. I thought it might prove helpful to repost the photo and write a short article on the subject, since I continue to see questions from others regarding the subject.
The photo shows the circuit board within the “Auxiliary jack/USB port/SD card slot hub” module (which I’ll refer to as the ‘hub’ in this article) that is part of the Infotainment system in the 124 Spider (and the MX-5), and it identifies where the four individual wires (and the braided shield) of a USB extension cable need to be soldered to the board for each port you wish to relocate. You could extend both ports, but I would think you would want one to be easily accessible for a thumb drive.
Keep in mind that you can not make use of a hub port that has a device plugged into it’s extended port; it’s one or the other. Ideally you should be removing the hub port being extended, but it is not necessary. If you do extend both ports, Sergey (ssh16 in the MX-5 Miata forum) has made a stl file available (free) to 3D-print a nice cover (looks similar to the hinged cover for the SD card slot) that blocks and hides both hub ports to keep you from plugging devices into them.
I was not trying to suggest that the method described above is the ideal solution, but rather to describe how it can be done if that solution was being considered. Of course, it is much easier to find the ideal cable and use the intended USB ports.
⇓ Here is an alternate solution suggested by abearman to providing USB ports at the rear cubby – a RapidX X-5 2.4 amp charger that plugs into the 12 volt outlet and the 5′ cord can be routed under the center console trim.
⇓ John M. emailed me after I posted this article with a photo of his iPod connected to a hub USB port using a “Noodles” cable, to show that the cabling in front of the shifter doesn’t have to be an intrusive mess.
⇓ Harry neatened his phone cubby somewhat by using cables with a 90° plug on the male end.
⇓ Jacaso wired in an always-on Wagan Tech 2881 USB C charger into the airbag message panel. Since it is always on, he clipped the LED power indicator to reduce the current draw. He found that the blue wire is a hot wire (not switched) that made an ideal tap location.