I made a little vid on how I installed rear door speakers in our 2013 Sonic (Canadian version).
https://www.youtube.com/watch?v=oSwG9wKEVhI
If you're putting speakers in your car and it came with the "4 speaker" option (front speakers only) and you want to add speakers in the door for your kids or whatever, this is how I did it.
Note: The crappy GM factory radio does not have a fade option, even after the speakers are installed. They must have F-ed with the firmware in the factory just to p-us off. The "6-speaker" radio is the exact same in appearance, other than the fade option...why GM? why? Oh well, it is what it is.
https://www.youtube.com/watch?v=oSwG9wKEVhI
If you're putting speakers in your car and it came with the "4 speaker" option (front speakers only) and you want to add speakers in the door for your kids or whatever, this is how I did it.
Note: The crappy GM factory radio does not have a fade option, even after the speakers are installed. They must have F-ed with the firmware in the factory just to p-us off. The "6-speaker" radio is the exact same in appearance, other than the fade option...why GM? why? Oh well, it is what it is.