Here's a strange question:

Hi guys,
this one is gonna sound a bit strange, but here goes:
I'm a vollunteer firefighter and I need to install a siren in my ridgeline. I've done this in several cars and trucks before, but here's my dilemma with the ridgeline:
I can not find an access hole through the firewall. Most cars and trucks have a hole with a rubber grommet that has some wires running through it. Honda has done such a good job at routing and hiding it's wiring that I can't find a way from the engine compartment into the passenger compartment. I only need to run 4 wires through - so not a big deal. I tried removing the glove box because that's usualy the best place to start, but no luck back there.
Any advice? Are you of you a Honda tech that might know the answer here?
Thanks in advance,
Matt