DocGraphics wrote:I sealed up EVERYTHING that wasn't a factory drain hole.
The factory drain holes are a "V" cut in the floor pointing towards the back of the car, then bent down & then bent back so that the opening is to the rear that water can drain out yet the leading edge is where the metal is bent down thus blocking water from splashing in from the front.

Here's a quick diagram



As for water getting in from the drain holes I choose not to drive in the rain, unless caught in it (only once) HaHa
but the way the factory cut & bent the drain holes seems like it would not allow much in.

The membrane I used was "protecto-wrap" from Home Depot, it's made to seal around windows & doors in home construction.
It's a 1/16" thick super sticky rubber membrane w/ a plastic backing, comes in a 4" X 50' roll for like $14.
Was enough to do both footwells with left overs, I made it go up all the sides a couple inches too for a "bathtub" effect.