Here are the promised pics. You can take the compartment out (5 screws, one in the back) and then just drill away. I put a grommet in for the speaker cable. I would NOT recommend putting the switch where I put it, since it interferes with the operation of the cup holder cover thing. Putting it on the other side is better. 3/4" drill bit kind of works, but you kind of have to jam it in. I used a 1/2" bit for the speaker cable. I want to find a 20mm ID spacer/washer for the switch since it has to stick out that much to not interfere with opening/closing the cup holder. Oh well.
http://farm3.static.flickr.com/2697/4059085245_7216a33b38_b_d.jpg
http://farm4.static.flickr.com/3506/4059085249_b0dc0150c4_b.jpghttp://farm3.static.flickr.com/2511/4059085233_14408a7dcc_b_d.jpg