I put some foam in the steering column hole and added some black duct tape inside and outside of the firewall to help hold the foam in place. I also used the tape to plug all the other little holes in the firewall. Easy to replace if and when it falls off. Works pretty good in water too. Minimizes the gush of water the dumps on your feet when hitting the deep stuff.I have the Polaris one for my 2011. It was four pieces, two for wheel wells and two for under the dash. Blocks off a lot of air coming in and dust. However there is still a large hole where the steering shaft goes thru the firewall. That is where the hot air is coming in now.
later