The problem is worse than just where the wires go.
I'm betting that your Subaru has separate turn signals (yellow) and brake lights
(red), which means that both of them have to feed to one wire that goes to one filament on the egg, which means that when you activate one light
on the car, the egg bulb/wire will feed the current right back to the car and light
the other bulb.
You need a diode-matrix block to stop this from happening unless your Subaru has one included in a factory towing package (presuming one exists and you have it). Otherwise, you will need one of these
, which you can even find at Wally or autoparts stores.