I certainly wouldn't "equip" someone else's car. I'll equip mine, and advise them on how to equip theirs if they ask. But it's not my place to hide stuff in their car that they would never find in the first place.

I guess this thread makes me appreciate my wife's truck a little more. I call it "The RCP" (she hates that!) "Rolling Crap Pile". But whatever you need - be that gardening tools, plumbing repair items, a bazillion half-consumed bottles of water, or a Sawzall ... you can bet it's probably in there somewhere.