need easy source 12v in 04 impala trunk

I want to put a small Bazooka powered tube in my trunk and need a convenient source of 12V to tap into. Doesn't matter if it's switched or live as the tube can be powered either way. It's a fairly low--powered amp and won't add much load to an existing circuit. Not looking to run a new wire from the front--my days of multi-amp systems & window rattling are behind me :)

I would be really wary of trying to tap a circuit when you don't know what else it's supporting or what it's rated at (5-15 amp fuse or more, etc.). There is a lot of risk involved where you could cause electrical system issues in other parts of the car. The smallest bazooka amps run 50 watts. That's a minimum of 4.5 amps you'll be trying to pull through an existing circuit which may not have the headroom for that. If it's a 100 watt amp, even worse. Running wire is never fun (I've done it enough too) but safe. Impalas have some easy holes to get through the firewall. For safety and peace of mind, I would consider buying a $20 amp kit, run it down one side and hook it up at the battery the right way. No more than 1 hour on the impala.

I would agree 100%.  OEM systems are not designed to have much extra capacity on them.  The wires are the aboslute smallest capable of delivering the designed load (saving GM money and weight).Kevin Pierson

My thinking was a 50-watt amp is only using 2-3 amps on average and I don't listen to very loud music anymore--especially as this is a factory system that doesn't sound good cranked up. A circuit for something like the trunk release needs to carry quite a few amps but 99.9% of the time it isn't used. I thought maybe someone would know of such a rarely-used source. I haven't had to wire up a system in years. Getting through the firewall isn't the hard part--it's removing all that trim, back seat, etc to run the wire to the trunk. My Aurora had all the power you could want under the back seat so that was easy. Everything else I've owned lately has either been a SUV or minivan and they all have had high-current accessory power in the back.