To put the two electronic boards plus some wiring, I made a case that fits inside the rear cup holder. Conveniently there is a 12v plug just aside. I need 3 cables: the 12v, the connexion to the OBD plug in the front, and the connexion to the rear LCD. I re-purposed old Lemo 3 way plugs, a perfect fit.
To hold the LCD panels it appends I have a Sonic the hedgehog plush on the back of the car, why not try to mimic the power-up monitors of the video game ? I printed this enclosure in PETG because I had bad experience with PLA on direct sunlight. I tried to have an ajustable, stable and discreet design.