2010 mazda 3, getting through the firewall

[Cheese]

I was curious how you guys got through the firewall in the doors and stuff to run the wires through.
I'm going to be hooking up a sub + amp and have been looking around for some picture how-to's to do the wiring.

I've been looking around both this forum and others and the best I've come up with is that there is a 50/50 chance of a plug being behind the glovebox.
A link to an already made picture how-to or an easy to understand blurb of how to do the wiring would do me wonders

Thanks in advanced
If I left out any info, I also apologize in advanced, just ask and I'll reply a.s.a.p.

[dave2010GT]

There is no plug behind the glove box in the 2010. I found a gromet behine the drivers side vent to come in through which on a scale of 1 to 10 was a 20 get through.

The easiest way to do it is to drill a hole behind the glove box and then seal it after you run the wire through.