crunktastic

So, I should have asked this a while back........

When I fixed the creaking problem with the driver's seat, I noticed that ONE of the 4 mounting bolt locations actually goes through the floor panel of the car, as in an open/exposed hole. The hole for the bolt is located at the rear of the driver's seat, closest to the center console. When the bolt is out, you can look through the hole from inside the car and see the ground (same looking up from underneath the car)--- there's no insulation or seal for the bolt. This goes the same for the front passenger seat as well. Judging by the fact that I did not change anything with the passenger seat, this is normal.

Is there any type of sealant/seal I could get to prevent water from getting in, and should I put anything on the threads of the bolt to prevent it from rusting?