Maybe you're planning something but just a thought, not like I'm some sort of fabricator but would it be advantageous to close out the bottom leaving the side open with some sort of removable louvered panel or duct.
https://www.ebay.com/itm/Tilted-Pair...-/183635037710
This way heat could escape while directing fresh air to the coolers. Plus it could also protect the coolers from all the rubber that's gonna be tracked up there.
Keep up all the nice fabricating work, I'm amazed at your engineering craftsmanship.