I have a 94 854T and also added a sub in the trunk which required direct power from the batt. If you look on the drivers side under the hood there is a fuse panel, if you take the cover off of it by removing 3 or 4 screws you can see a bundle of wires going through the firewall. If you lay on the floor on the drivers side, you can also see these wires coming through. Depending on the size of wire that you need to feed through will determine how tough this will be. I had a #12 wire and got it through with little problem. I snaked that wire along the interior trim pieces along the door sills to the trunk with no problem also. Good luck!