I realize this is an old thread, but it keeps coming up when I search and there is some incorrect information in it.
All S550 mustangs come with the Super 8.8 differential. There is a carrier break between the 3.31 gears and the 3.15 gears, so if your car came with 3.31, 3.55, or 3.73 gears and...
2018 Ford Mustang Center Dash Speaker by 700hp5.0 posted Aug 23, 2020 at 10:28 AM
GTP, thanks for all of the information. I took it upon myself to measure the speaker in dash, here is it's impedance curve.
I've also done it's response with REW if anyone is interested.