I think it's friggin annoying that the outlets are tied to the accessory bus or whatever you call it. I want to rewire it so that the one in the armrest is always on. Anyone done this? I don't think it would be that hard.
I think it's designed like that so you don't accidentally leave something plugged in and drain your battery. If you wanted to, you could just run a wire through the firewall and straight to the battery.
you just need to rewire the white/red + wire that normally powers the socket to a constant hot source that is as strong as or stronger than the original + source (by strong, I mean tolerant to current draw). Maybe use some 16 gauge extension wire to tap an unused constant underdash fuseslot such as fuse#3 with an add-a-circuit. Fuse#3 in Cdn models powers the stock DRL load, so its likely strong enough to handle this job. There's another constant hot unused fuseslot, but I can't remember exactly which one it is right now.
Or as willy said, straight to the battery (through the firewall) will definitely work- as long as you fuse properly.