Going through the grommet

This is a question in regard to an earlier post. I am running a coax cable from the bumper into the cab. FL Forester recommended the rubber grommet behind the drivers seat. Perfect location and I have located that. My question is the proper method to go through the grommet? My concern is that the seal may be compromised and I would have water leaking into the cab when running in wet conditions. Considering the carpet covers this entry point I may not notice until a significant amount were to build up. Do I assume that a small hole in the rubber gasket that will stretch when I push the coax through will have sort of a "self-sealing" effect around the cable? Is there some type of sealant like hot-glue or other that you apply to assure all is tight?? Thanks!!

 

The gasket is pretty soft. I would cut(drill?) a small hole, slightly smaller than the cable and then slit it just big enough to get the end through. Get it all in place and then apply a good dose of urethane sealer around the cut. It is static so should remain watertight.

 

Un tape the grommet and push the wire through with the rest and re tape it. Poking a hole will just allow water to get in but no way to get out. I've already done it twice, once for my bed lights and for my aux back up lights.

 

Do it like this guy did...