12 volt DC accessory socket kit

I would like to install on my 1800 for charging cell and using GPS. As I understand from Hal's site, this accessory is placed within the front side pocket - either left or right. Supposed to be plug and play. Since I have Ram mount for left side - thinking about putting in left pocket. I also have the volt meter installed which is plugged into the accessory plug underneath the left front pocket.(on pre-2006 this accessory plug was under right side) Wondered if there is another available plug for connecting under left front pocket or would I need to obtain another wiring harness which would enable me to plug both the volt meter and accessory socket in this single connector.

Since I haven't seen one installed, wonder - do you just lay in bottom of glove box or is the plug actually mounted to the inside of the box? Any info or guidance would be appreciated.