My car broke down one day a few miles from home and a trooper happened to come along and offered a ride home so I could get to a (pre-cell) phone and call for a tow truck. As I got in the front passenger seat, I suddenly remembered that I was coming from picking up a not-small bag of fairly fragrant weed, which was in my right hand pants pocket near the door and away from the officer. Couldn’t suddenly change my mind about the ride and get out, because that would seem strange, so I just rolled the window halfway down like I was on automatic, and he didn’t say anything about it. Then spent the next few miles having really, really normal, non-suspicious conversation until he dropped me off at the end of my driveway.

Another incident, where I was driving home in the middle of the night, and was falling asleep, so I made the responsible decision to pull over into a safe area to get a nap and not be danger to anyone. Woke up to a flashlight tapping my window, surrounded by officers, wanting to know why I was there, as if it wasn’t clear I was sleeping. After explaining that I didn’t want to kill myself or another person from falling asleep behind the wheel, they decided my car needed to be searched, and I didn’t care because I didn’t think anything was in there, just said fine, let me nap in the back of your car while you waste your time. They found in my glove compartment a small wooden box, that I had never seen before, that had a minipipe and weed leftovers, and the only explanation I could give them was a recent hitchhiker must have left it there.

Totally unbelievable, only thing I could come up with to explain it, and for whatever reason they let me go while confiscating it. And then forced me to get in the car and start driving again in a sleep deprived state, but at that point I was so deliriously awake that I got home ok.

edit: yes, that last one happened before I was aware of how often cops plant evidence in cars