Hi, I'm new around here but was hoping you guys or gals might know the best place in the trunk lid to tap into for a brake light. I bought a spoiler for my wifes 09 LE Corolla and put it on but am having a hard time finding a decent place to run the brake light wire without having to run it out of the lid and down to the brakes. It looks like there are a few wires up in the trunk that aren't attached to anything but I can't figure out where they go. Any ideas?

If you look for the brake light... meter the 2 wires coming of the brake light. One of them will read 12 volts when the brake is pressed. That is your brake light.

I have a question about this procedure, does it means splitting the signal from one of the rear brake lights?. Do I have to raised the fuse load (amp)?. Thanks

You'll want to set it on the 12 volt DC scale. Make sure the black lead is plugged into the ground socket on the meter and the red lead is plugged into the Volt or V socket. Then we want to test the power at the 3rd brake light socket connection. Most likely you have a bad connection at the 3rd brake light where it mounts to it's base or at the bulb socket. You can remove the bulb and just check across the contacts in the lamp
for voltage while a helper applies the brakes. Make sure the key is on. If you don't measure any voltage there then you can slide the assembly off of it's bracket and measure the voltage across the two contacts in the base of the lamp holder. What usually happens is the plastic melts in the housing and you get a poor connection.
Thanks

Ratchet Straps