What is the rectangular blank next to the 12 volt cigar port under center console for?

I think there is variation between different models.

But on my 2012 v, I think that plug replaces the switch for heated seats (which I do not have).

I popped that plug out (no clips to release or anything, it's just a snug fit that can be pried out pretty easily) and installed a digital voltage gauge in its place. The 8P connector immediately behind the plug has a red wire in pin #4 and black in pin #7 for +12V and ground. The +12V is switched on in ACC and ON modes, off when the car is OFF.

 

I have the heated seats, so that blank is in use in my car. However, the panel it mounts in also pops off and there is a fair amount of room behind it. I mounted a double Anderson PowerPole outlet there (which I need for other stuff) and wired directly to the fuse box with an "add a fuse." Top outlet unswitched, bottom outlet switched,

 

Interesting -- circle back after installation and let us know the fit.

 

I used that blank to add a small led lamp that shows when my second 12V battery is charging (in parallel with the regular 12V battery).

Which digital voltage gauge did you get that fits in the space?

 

Something off eBay for a couple of dollars. It must be a fairly standard size. The body of the gauge fit snugly in the rectangular hole, and it has a thin frame around it to make it look nice ... enough.

BTW, I have digital voltage gauges, either permanent or cig-lighter removable, in all my cars. I use them to keep an eye on battery health, charging voltage, parasitic drain, etc., which I find much more useful than arbitrary color-coded charts about whether my battery is good or about to explode. If I know what the readings are when I know the car is running fine, I should know when something went wrong.