Each of these plugs are $90 at the dealership. Buy a pair of plugs from me and then you can buy 2 sets of these lights and instantly improve the lighting in your trunk. All in, you're looking at only $50 for significantly improved lighting in the cargo area. 
The kit comes with 2 plugs and 4 terminals.
The install video can be found here.
If you want to improve the lighting of your other dome lights, check out these lights from Auxito. Use code "BADLAND" at checkout for 15% off your order.