[WRXRacer111]

What I did and what I think the Retrax instructions suggest, is drilling holes in the oval-shaped plastic plugs at the front of the bed. Route the drain tubes through there. I just used a utility knife to cut an "X" through the plastic plug and routed the drain tube through that. That way you're not drilling any metal etc. and it's pretty easy. Worse comes to worse, you can order new plug or, pop them out and spray them with spray-on bedliner to seal them.