I ran a cable through the wheel wheel into the cabin. On the bottom left in the driver foot area are a few rubber grommets where you can go through the firewall easily.
You can make a hole in the rubber grommet that fits tightly the power wire so that it still sealed and keeps water outThat's a good way to short out the fuse box. It cannot handle a sub.
Going through a rubber grommet works but they are there for a reason, to keep water out.
Proper way if you cannot run it with the wiring harness that enters the firewall is to drill a hole and use a sealed cable gland. Few bucks for a pack off Amazon.
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