How bout getting in the back and having someone spray the thing with a hose. Locate the leak source, apply some caulk, throw away that mildewed mess, and be happy. But, my experience is that if it leaks enough to soak a carpet it's probably leaking at the bed rail/camper shell seal. The shell install folk use cheap, open-cell, doublestick, foam tape that the wind blows out fairly quickly. If that's where your leak is take off the shell, clean the surfaces and reapply the foam. Better yet find a better material to seal the gap.
Oh, and to keep things from sliding around: go to a store that sells farm and garden supplies and buy a horse stall mat. They will more than cover your bed, are reinforced 3/4" rubber, and just slide into the bed. The only problem is cutting them to size around the wheel wells but a circular saw and good measurements do the trick. Don't try to cut that stuff with a utility knife...you'll be at it all day cuz that rubber is TOUGH! The stall mats are less than half the price of a cheap bedliner and you can drop a horse into the bed and it wouldn't dent the steel.
If everything in the back is getting wet you may be better off just removing the shell and surrendering to the elements. The rain gods are some pretty powerful folk...
If, after this, you still feel shot down, I would suggest that maybe you should get rid of your truck and get a car...truck guys improvise and overcome and they never let a little leak shoot them down. (and real truck guys don't carpet their beds either).
Last edited by momule; 07-29-2014 at 12:39 AM.