Front Bumper Solution problem

I have and A8, '97. One of those triangle headlight washers (not functional, hoses are disconnected and sealed) was broken down from one of our car washes - I didn't see that when it happened, so couldn't return for the piece.
Now I have a hole in a bumper instead of the washer. Square one

Is there any cheap solution to get around this? Ideally I would need a new bumper or get this one fixed ($200-$250), but I don't want to do that, since I'm planning to sell the car soon. Ideally, if some kind of plastic pieces or something could be bought, that could be glued in there would work. So I could break the second washer and cover both holes on a bumper.
Any ideas are welcomed. Thanks.








