what a mess under mine, with rusty circles in the paint. If I can figure how to post pics I will, but in short I suggest pulling the step inserts. Make sure the drains are clear, mine had gobbs of factory paint/sealant 1/2 plugging the opening.
Drill an extra drain hole towards the front of the step area... The factory drain hole location is uphill from the low point. I have left my three plastic screw plugs off, because I remove the plastic step to inspect for water whenever it rains. A real nuisance!