My first heavy winter in Arkansas, we got a lot of snow and ice. After two days in the house, I HAD to get out - needed essential groceries, and was going to have to go to work the next day. The roads had been plowed, except for the little ones, and since I was half a block from the main road, I figured I'd chance it. Got the van stuck in some slush halfway into the street and couldn't get traction. Was panicking - until a total stranger in a huge pickup pulled up, tied a rope to the van, pulled it the rest of the way into the street, made me pull up a few feet to make sure all was in working order, and took off with a smile. Was so grateful.
Also, as a young adult (first real job) had just gone to get my nails done with a coworker, and was on my way to work. I was driving on a section of road where two lanes merged to one, and there was a lot of industrial traffic. I felt a pop, and my left rear tire blew. I slowed down, stopped just as the lanes converged (was in the last ten feet of the lane that was disappearing). Coworker called and got our boss to come get her (!) and left me all by myself, with damp nails and in work clothes (nice skirt and heels) on the side of the road with a flat. As I am trying to get the stuff out to change the tire, an old truck driven by an older man and his grandson (kid was maybe 5) with fishing poles hanging out of the window pulls up behind me. The driver helps me lift the spare out, and then insists I go back with his grandson and get out of the road. He changes the tire, follows me to a gas station to inflate the spare (which was very low on air) and even gave me the money for the tire pump, since I had no change on me. I still think of that man every time I look in my trunk and notice the spare tire - I felt like I'd had a guardian angel visit me.