what to do about neighbors parking like assholes?

Call the landlord if applicable, or the police. A polite warning of involvement of the authorities beforehand is recommended.

Always practice good conflict resolution, but do not hesitate to escalate if domestic attempts fail.

When someone did that to my sister, she simply wrote a note in bold letters and stuck the sticky note to the car window. It would be quite embarassing if that happened to me and I'd probably stop doing it after that.

My daughter had a similar issue a few months ago she lives in a complex and her unit is towards the end just as you need to turn to the very last unit.People where parking just on the corner where her driveway is and the turn starts.
They actualy ran into her car slightly and had to get the car fixed. But my daughter did go a couple of times and had to remind them in a nice way, that they are not in a good position and could they move the car as to not have their car damaged before the accident occoured.
I think by putting it back on their car they want safe,and they dont want scratches etc and mentioning that you can't always wait for them to come out first to move may make them think of their car more then yours.Hopefully that will to the trick!
Sorry I cant offer more advice,but do speak to them again.Good Luck!