This is a REALLY REALLY annoying level because of the camera angles. Half of the time you can't see what you're doing! First, jump on the grid and use the blast-up to turn one or two of them so you can then jump over to the right. When you're on the grid, go to the opposite side as the enemies are and use B to bash them off. Get all the enemies off for the shiney to appear. Sounds easy, it really isn't.

Now stand beneath the rotating baskets. Go over to the ledge to the left and jump onto it. Jump from there onto the TOP of a basket as it's right next to you. Ride it up to the top to get your shiney!

Super Mario Sunshine Walkthrough