To better power my car during car shows and cruises, I decided to install a dual battery setup in my car. I got the parts I needed for this job (except the battery) from Summit Racing.

I used the Summit brand battery relocation system and the Painless brand current control system.  My aux. battery is a Dekka group 31 deep cycle AGM.

Installation was pretty straight forward and went well. The instructions included with the kit were adequate. I installed the extra battery in the trunk and ran wire to the solenoid, which I installed in engine compartment. Since my car is a V6, I had plenty of room to work with for installing the current control solenoid.

I then installed the control toggle switch and status indicator lights just below the map holder section of the stock dash. this way the toggle switch is out the way, but still accessible if you know where to look for it. 

I also added a feature to my car to compensate for the extra 70 lbs of battery in the trunk. To help keep the car's stance level, I installed an Airlift 1000 inflatable boot system for the rear springs. This is a similar set up to what one would use for the front springs in a truck with a snow plow on it. It might've been overkill and not really necessary, but I felt better having the extra support for the weight of the aux. battery.