Trying to figure out the best way to run power wire through the firewall to install an amp. Probably 8 gauge wire but possibly 4 gauge. Read in the 4th gen forum that there is giant grommet that can be used. I was assuming the chassis of the 4th gen and prime was the same. Maybe not? Anyways, I've attached a photo of what I believe to be the grommet. If that is the grommet, how would you get the wire through? concerned about poking through there and damaging something underneath. Also, anyone have a photo of an install that shows the wire route through the engine compartment to the battery terminal? Thanks for any info.