This is what I do too. Sometimes I get out of the store only to find that the most beat up hugo parked right next to me. It's quite comical sometimes
I find that the shopping cart return is usually the least likely place to actually find a shopping cart, so I think it's pretty safe too. Which brings me to my own personal pet peeve...people who are too darn lazy to walk the shopping cart to the return, even when it is just a few feet away.
You forgot one: 7) Park on the highest point on the parking lot. That way all Runaway Carts will Run Away from you I know that in some places Parking Lots are flat, but I'm from WV.