Any ideas for safe transport of spare gas for the gen?

My generator box is vented. Never start gen without opening box. Otherwise, the cans are locked by cable and pad locks in truck bed on plastic trays. Already had one attempt at stealing the fuel. The locking cables foiled the fools! My generator box have exhaust fans made for marine applications, no spark. I still open box and air it out before remote starting gen. Also remove fuel cans during operation !