Before I traded in my 1999 f-150 I pulled out the custom box w/2' six's and a rockford f400 amp,they fit perfect under my rear seat of my 2009,and is the same color as my new interior.There both about 1 1/2 years old.
My question is will they have to pull out my head unit to hook up the wires,fuses etc. to install the amp and subs,or will all the work be done in the rear.

 

In short, yes they will have to pull out your head unit, most likely to install the remote wire. besides that the they will have to run a power wire from your battery through the firewall, to the back of the cab (where the amp will be) then splice into one of your door speakers to install a RCA converter.. So almost all of the work would be done in the back, except a few very small things.

 

I dont have a problem with that as long as it's a good job,I wasn't sure.
It looked like you could of just had to remove the amp and install the box,whats the remote wire,how importants that.
Thanks

 

actually, if you are just adding a sub, you technically don't really need to even take out the radio. The remote wire turns the amp on when you turn the key on. you can tap into a key on wire in the fuse box at the passenger kick panel.
you will also run your battery wire from that side as well, so you can do them both at the same time, and then you can pull your inputs for the amp from your rear speaker wires that you can tap into from each side.
You can ground the amp to your seat mounting bolt back there and you are all set.