So my subs are not working on my door

 

I had a 2010 ford mustang with the shaker 500

 

Any clue what the installer missed could I just need an amp

I doubt you need to buy an amp. I had the Shaker 500 in my 08 Mustang GT. I have the Z110BT (same hardware) I heard about known issues with popping so I purchased the recommended wiring harness $120-130) instead of the standard $20 harness.

 

http://www.crutchfield.com/App/Product/ ... =0&tp=3486

 

Not sure if this could fix your problem.