i've been looking a the back end of the xD and there are some holes already covered up some rubber grommets. Anyone thing that it's a good idea to run the power wire underneath so you don't have to deal with going through the firewall?

Yang

 

I really wouldnt recommend that. Besides weather (obvious), you would run the risk of fraying the wire if you bottom out or accidently jump a curb. Unexpected things can happen and all.

Going through the firewall can be difficult, but it can be accomplished if you take the time to do it.

I know others have taken the dash out to get to the grommet for the firewall. I just reached up and found the grommet. Found an empty spot in it (theres a lot of room to work on the outside of it. Carefully cut a hole and run your wire through it.

Now, I was using four gauge wire, so it was very rigid and I could just force it through to the engine compartment. If you are using something thinner, it might be a little more difficult.

Going through the firewall is by far the preferable way of doing this. To each their own though. Good luck!

 

I suppose you COULD have reached up to do it, but with me having a clutch pedal in the way I opted to take the dash out and cut a slit in the grommet then push my 8 gauge wire through. You can barely see it in the engine bay, as I ran it through the rectangular tube with all of the other factory wires, and you can't see it at all inside.

Also, do NOT try and remove all the tape that's around all the wires going through the center of the grommet. You will not be able to push the wire through, as below the tape there is a layer of double sided tape. You cannot get the double sided tape off that is between both sides of the grommet, therefore you won't be able to pull anything through. I tried, and wasted a good hour. Hah

 

i took out the speedo and the bottom dash and finally found the damage gromet lol... i was using 4 gauge so i just forced it through the gromet.