Just installed my MX4 Bakflip, drilling holes for drainage...

So I am tempted to go get some sleek silicone tubing (instead of the corregated stuff the MFG sends) and drill a hole (required any way you do it, so it seams) up near the top of the bed to get the water out ASAP instead of minimizing the factory drain holes / enlarging them. Has anyone gone this route?

 

Yes. 1/4 × 3/8" hose barb. Black corrugated tubing is invisible in the dark corners.

 

I used the factory drain holes on my 2014, found a brass fitting that fit the factory bed holes and had a barbed end that fit the clear plastic drain hose. Have had no water issues, i don't believe the amount of water leakage is substantial.

 

I hope you put silicone under the rails sides because it leaks under the rail rubber seal. Also in front bulkhead corners. Just close the cover and look at top corners you'll see the daylight.

 

Did you run into any issues with drilling the holes in the top of wheel well? Anything in the way that I should know about before I do it?

 

No holes drilled. Drains fine. Unnecessary holes.