Loud and Clear
So, what would be the best way to show someone that the spot they parked in is reserved for someone else? You could easily make a note and leave it on the car or stick around and wait to see if you will see them and tell them about the error. But, just to note, you could also engrave it on their car.
Instead of leaving an angry letter, this person decided to let their keys do the talking.

Loud And Clear
Two for One Deal
What would make this brilliant is if these two drivers planned the whole scene we see here. After all, they are tiny cars and can easily share one parking spot. But, it could be a different case here as these drivers may not even know each other, but it just worked out perfectly.
This seems like some kind of betrayal, given that both cars are of the same make. Oh, the irony!

Two For One Deal