What is stock speaker wire gauge on 97' corolla?

[kevmac]

I was trying to figure out the maximum load on my stock 97' corolla speaker wires so as to run two speakers off of one hu instead of 4 and then I realized that this may not work like I planned.
I assumed that I could run a 4 channel (22 rms per channel) hu as two channels and get nearly double the power. So I ask: can I double up the wires in an hu to make 2 channels with twice the power?

I bought this and I am planning to purchase an amp for the front speakers. The rears will then need a boost while being on the hu to be able to be heard at all.