I bought a complete carpeted mat set on E-bay from Uncle WoWo's Floor Mats and stuff. They have the best coverage for the rear seats including the second row captains seat configuration. this covers the walkway between the captians seats and 3rd row seating. Price is good and he has 100% feedback. I should have mine in a week or so.
I just recently bought the nifty brand extreme mats for my 04 PSD crew cab. These are rubber formed mats that will catch most mud,liquids, and trash. They fit the truck great. Our sponsors carry these I believe with free shipping in some cases.