Bed Slide Securement to Bed

Picked up a second hand SR10 Bedslide today, and before I go drilling holes in the bed to secure this sucker, wanted to pick the collective brains of the TW Bed Slide crew. How do you have yours anchored down?

 

bumper

 

I helped a friend install one a while back. Measure 6 or 7 times then drill. We used very large flat washers, something like 2 inch, on The bottom. Under the plastic bed is a number of verticals ribs. Try not to damage them as that is where the bed gets its strength. Regular silicon sealant will keep dust and water out. Go slow, take your time, it works well when competed.