I keep mine under my rear seat. No rattling, no thieves, no rust. I intended it for a short-term solution, but I'm thinking of leaving it.

 

I generally don't like to mount any loose accessories outside (jack, rotopax, etc) as I always fear someone will try to steal them or in this case the jack will always get harsh overtime due to exposing to the elements outside if you don't keep it clean. I kept mine inside mounted overhead by the rear roll bar.

 

Mine's in the corner of the garage with spider webs all over it. I hate the dangerous, rattling, dead weight SoBs. I carry a bottle jack in the cubby bin under the rear deck, along with the stock jack stuff. Good to go.