[Player]

Mil1ion: Where would I find one of those rubber sleeves?

[MIL1ION]

I am thinking you may have to alter something like a rubber cork.
Of course you could always cut the threaded metal end off and drill out a tire air valve with larger hole

Grommets can be found at camping supplies stores.

[Player]

Don't grommets require grommet guns?

[MIL1ION]

Nope, Just a hammer and punch.

Camping supplies places sell the whole kit (without a hammer)

[Player]

I'll have to look into that. There's not really a good option for protecting the vehicle outside. Need a third car garage.