getting wires through the firewall?

Where should i go to run some wires for a fan switch inside the car. I'm looking for somewhere i can go where there are other wires around so no drilling is envolved. Any ideas?? Need some help here thanks.

I had a hell of a time with this too when I put in my fan switch, clearly the hardest part of the job. I, too, wanted to find an existing wire passage but none was very doable to me.

Finally, I punched a small hole in the double rubber boot that surrounds the steering shaft and dragged my wire through there. No drilling and minimal "damage" to the car. Also, the rubber boots provide a good dust/water seal around the wire AND they do not crimp or scrape the wire.

I'm happy with this solution.

That's the easiest way, I have done few wires this same way...
There's anough room to do it and it's secure place.