How can I unlock the bootloader on GM 2014+?
In the engine bay, remove the 4 plastic covers with 3 differents screw type. Be patient, and the order is very important. You must remove the cover on the right side first, one screw is very tricky to remove 'cause it is placed where the windshield washer fluid container is placed. So, you have to remove it first, there is 4 screws (different size than the plastic covers).
Once your done with the plastic covers, locate the 6 pins connector with these color coded cables: blue, gray, brown, black, red on white and green on white. Don't confuse it with the other 6 pins plug (blue, gray, brown, black, orange on white and green on white).
Once located, with a flashlight (but easier with a headlight) follow the cable on the female side of the 6 pins connector to the jounction box. Once located, use a short phillips screwdriver (I uploaded the photo of the screwdriver I metal-saw to reach the location). There is 3 screw there.
With the junction box now open, you will need to make a custom USB female connector by tapping on 4 cables in the box: red for data+, blue for data-, black for ground. For Vcc use a cable running from the positive pole of the battery. But, don't forget to buy a DC converter from 12v to 5v at your local electronic store.
Now, you can connect your PC using a regular USB cable to your car.
To enable fastboot mode, you will need a friend. Because, you now need to time engine start with the hazard, the trip reset button and the passenger door.
So while in the drivers car, turn the engine on while holding the trip reset button. When you see the check engine indicator flash 2 times, the passenger needs to quickly open the door then push the hazard button. If the procedure worked, the engine indicator will blink rapidly for 10 seconds. During this period you must issue the "fastboot oem unloock" command from the terminal.
If the procedure fails. Wait 2 minutes and retry.
Alternatively, you can buy on eBay a pre-rooted/unlocked ECU. I'll post a procedure to replace the ECU by yourself once I'll figure it out.
How can I unlock the bootloader on my Subaru 2014+?
Open the glove compartment, you'll see on the upper left a female micro-USB connector, connect your laptop into it and issue the "fastboot oem unlock" command. Bingo!