The ground clearance stickers, as far as I have seen... are the models with the side sills. I also think they are a guide to the dealers...
I wasn't warned about it when I picked up the car... if it was something they wanted passed on to the consumer they most likely would have left something inside the car, hanging off the glove box or somewhere warning us and telling the dealer that it is only to be removed by the buyer...
I have the SE with the sills and the clearance isn't too bad... 6 inches or so I think...
I wouldn't do 50 over a speed bump though...
It isn't like you have no clearance on it... don't be bothered by it... it makes the car look even sweeter!!!