Do it yourself. Really. If you need help I come up to Dallas about once every six weeks.
You should really consider doing it yourself, its not that difficult.
If you bring it somewhere, buy the directions to install and remove speakers, then tell them the following:
DONT CUT WIRES BEHIND MY HEAD UNIT
You may want to return the car back to stock someday, make sure you provide them with the correct wiring harness from SoS.
THIS IS WHERE I WANT TO MOUNT MY AMP
I like to mount the amp in the trunk, and I live in Austin heat has never been a problem. Others like to mount it behind the seat (which requires less cabling but reduces leg room). WARNING: There is a cable behind the drivers seat that can be snapped if they are not careful when mounting running wires.
DON'T DRILL ANY HOLES TO MOUNT MY AMP
If you put it in the trunk, buy the SoS trunk panel. If you put it behind the seat you can mount it to the cover below the rear window towards the floor. If they don't know what they are doing and drill into the sheet metal they can puncture the gas tank.
DON'T DRILL ANY HOLES TO RUN WIRES IN MY CAR
There are two holes in the firewall, one behind the passenger seat, one behind the drivers seat.
USE THE JUMPSTART TERMINAL IN THE ENGINE BAY FOR POWER
No need to go to the battery, if your amp is in the trunk or behind the seat the best power source is the jumpstart terminal.
WHEN MOUNTING SPEAKERS IN THE DOOR PLEASE READ INSTRUCTIONS FOR REMOVAL/REPLACEMENT
Lots of audio installers will break the plastic tabs that mount the door panel to the door. They are brittle and if you overtighten them they break.
DECIDE YOUR PLANS FOR THE SUBWOOFER AHEAD OF TIME
If you want that boom, boom, boom......If you are going to install a subwoofer, I would provide it to them. There are a lot of great solutions out here today. Angus, Sylora, and a few others offer plug and play solutions. IMPORTANT: If you are not going to install a subwoofer at the very least you should run speaker wire to the passenger footwell from the amp. You should also make sure that you use a 4-channel amp cable so that you can easily upgrade in the future. I don't have a subwoofer today but I can definitely see myself getting one for Christmas!
