Just finished splicing that wire in. I ended up using about 4 inches of 20 gauge and 2 butts, and was able to feed it down through with a wooden grill skewer. Trunk lock is working again
I hope that's the only wire that is bad, I guess I will find out eventually.
My total cost was about $3 for the butts at the hardware store. They gave me the wire free since it was so small. It took less than 10 min. I can't believe that Subaru wanted $340 to fix this.
Thanks to everyone that posted, you saved me huge!