[767Jockey]

Unless I am missing them, I don't see thick panel rubber grommets in McMaster Carr for using on my firewall and other panels in my car. I'm about to start the electrical part of the project. It seems that a grommet to fit a 1/4" thick panel is the thickest panel thickness I can see in McMaster-Carr, and even then it is only in very limited sizes. As best I can tell my firewall is about 1/4" thick, and then I have an aluminum panel over that. Also, I have wires to pass through bulkheads and such, all of them seem to be 1/4" thick. Any ideas where to source this stuff, guys? Thanks.
Doug