Alley Etiquette

We have new neighbors across the alley (in Illinois detached garages are very popular, so we have an alley that all of our street's garages, and the block behind us share). The benefit of that set up is that we don't have exhaust and chemicals from the garage coming into the house. We also have a gorgeous street view in the front because when you drive down our actual street you don't seen ugly driveways, trashcans, or garages full of junk. The downside is that it's a very narrow space that only moves one way.

Our old neighbors were not the most considerate people. They constantly blocked our driveway by parking in the alley, and frequently their kids' toys would be in the middle of the alley. When we saw the "for sale" sign, we were overjoyed. Last week the new neighbors moved in, so understandably we had a period of semi-blocked alley space. Today, however, there was a little red sedan that was parked directly behind our driveway for several hours. There was no unloading or reloading, it was just parked.

I have always been the type to write things that I would never have the courage to actually say to people. I probably should have walked across the street with the old neighbors and explained to them the issue, but I didn't. Now we have the same issue all over again. I actually wrote out a note to put under the windshield of the offending car and then chickened out. Do I walk over with a cake and say "welcome to the neighborhood, please move your car"? Do I just be the neighbor who leaves notes and never introduces herself? Do I not say anything?

We have a lovely neighborhood with very friendly people, but I really wish we could have neighbors that would understand the alley etiquette.