Someone damaged my car, now what?

Hoi allemaal,

My car was parked on the street and someone has run into the side of it. Well they were “so nice” to leave a message that they have made the damage, both with time and date, but no phone number or name. They also have written “Auto 1998” which doesn’t seem to be an identifier as neither any cars in the surrounding have a number plate with this and house numbers are in the tens?

So now I have a damaged car and a message, what should I do?