Assuming they're all the same no matter what year.... I would recommend you be careful. As Wilddude said, you can take em out and clean them. However, if you start poking around with a screwdriver trying to pry the tabs out, you can very easily ruin the seal. Then you'll get water inside everytime you wash your baby.
JonB can sell ya new ones, and I think they're around $42 each (you can't buy the seal separately).
I think JMcGuire is right on the money, Sheyster. For the newer cars, you would either have to cut holes in your fascia for the tabs, or (yikes) glue the covers on.