I need to know where the firewall is to connect my power cable to my battery please. i wanna hook my sound system up and figured id find out before i started drilling Thanks

 

If you dont know where the firewall is you shouldn't be drilling anything.

 

wow!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

I have encountered such a problem like that, and I have read from Google research that you have to do the ff: I number it for you to be clear:
1. run the power cable:
2. Find a hole in the firewall of your vehicle. If you can't find a hole, you might be able to squeeze a power cable through the far corner of your hood, by the windshield and into your vehicle that way.
3. If you can't do that, then you'll have to drill: Inspect where you plan to drill the hole, and be sure you won't damage anything in the process.
4. Take it slow, if you are feeling really anxious, drive your vehicle to a stereo shop, and have them run your power wire through the firewall.
5. run the cable wherever it will fit nicely, and not be visible once you put the carpet back in place. Run it all the way to your trunk.
6. secure the cable. Use zip ties, or glue, or even velcro to make sure your power cable stays where it should.
7. run your RCA cable(s), interface cables and Remote turn on wire, be sure the negative cable is disconnected from the battery.
8. Pull your head unit out.
9. Disassemble any and all of the panels surrounding your head unit. Next,
10. pull up all of the panels, consoles and carpet around where you'll be running your RCA cable and interface cable.
11. Connect the remote turn-on wire to your head unit's wiring harness. If you are planning to connect more than one or two devices to your head unit's remote turn-on, you will want to look into installing a relay.
12. run the RCA cables, interface cable and remote turn-on. All of the stuff I said earlier about power cables is also true of RCA and interface cables.
13. Be sure your cable is not close to any moving parts, it is not rubbing against anything that will strip the insulation, and it is ` in such a way that it will not show once the panels and carpet are put back in place.
14. Connect the RCA cables to the pre-outs on your head unit, and be sure you know which RCA cable goes to which channel on your amp. Several RCA cables use color-coding, so it shouldn't be too difficult.
15. Plug in your interface cable.
16. Now, re-install your head unit.
17. Lastly run speaker wire Pull up the panels. Run the wires. Be mindful of where you plan to run them. Secure them. Make sure you have a few extra feet at each end of the speaker cable. I know this sounds stupid, but trust me. It's more stupid to spend all of this time running wire only to discover that it's too short. I hope it could help!

 

looks like you've made a good research huh. i've also done the same thing when i have encountered such problem with my car. thank god google is always there to have me some research.