Is there a better way to run RCA/speaker cables to a head unit?

I have seen people run them from the center "gusset" (which is where my cables are right now) under the dash to the passenger side, where they slip them between the sill cover and the dash... Problem is that my RCA cables will not fit through there...


I am not opposed to drilling through the aluminum at the bottom of the dash, but I can't even find a spot where it seems clear to do so...

Anyone else have any clever solutions?