Grn w/Blk stripe & Grn w/Red stripe are Lt & Rt backup lights respectively. They are NOT the brake lights!
I checked the current. Without the trailer it's 4A through fuse #30. My trailer which has side lights and tail lights added 1.8A for a total of 5.8A. The fuse is 10A so I see no issue there. You can test the current by pulling the fuse and touching the probes of a DC Ampmeter across where the fuse plugged in.
As suggested earlier, you can place a fuse inline with each of the lighting circuits: orange (tail lights), Blue (Lt Turn/Brake) and Blue w/Red Stripe(Rt Turn/Brake). This would protect against blowing the car fuses and losing your rear car lights in the event of a trailer short.
Given my trailer only pulls 1.8A, I won't need a relay. The existing 10A fuse can easily handle 5.8A. I'll use 3A fuses for the (3) trailer circuits.
I recommend getting one of those little plastic boxes to stow the wires when not in use. It makes for a neat job and keeps the plug clean.
I have a few pictures but don't see the 'Manage Attachments' button the FAQ says should be there. It's my 1st post ever so I'm sure I must be missing something.