1) A vagina that has been pounded so much by erect penises that it has become a resting place for said penises.
2) A nickname for a woman who has a tattoo labeled "boner garage" and an arrow pointing to her vagina.

A term used to reference cannabis/marijuana/weed.

A woman who loves/addicted to sex so much she refers to her vagina as a boner garage.

A "Boner Garage" is a place to park your lovely boner! Your significant other or that hoe Sheva that you met down the street could often serve as your "boner garage".

the biggest pussy/fag you will ever meet, 100% of the time referring to persons named Kaden Costello

A boner garage is a penis locker .
A penis locker is when a girls vagina can hold many dicks

Euphemism or slang term for a vagina.
Or
In reference to a promiscuous girls naughty bits.