Most clever location I've heard about personally was some guys in MN. who grew a pretty large crop on state property. They planted it right next to the freeway in a place where they no longer mow due to either budget cuts or some other "let it grow" program for tall grass. Can't remember why they don't mow anymore, but it totally camo'ed the weed and they pulled over regularly to tend it as though they were having car trouble or taking a leak.
On the unlikely chance that the HP stopped to check them out while pulled-over, (never happened), there was close to zero chance of the LEO checking all of the tall grass for pot plants and even if they did, nothing to tie the stopped car occupants to it. "Oh wow,...I'll be damned..."
