I'm using a Snugtop tonneau on my 09 DC SB, and I can't use these now. They work great when you've got an open bed, especially a long bed. They'll work with a short bed if you use the fork attachment on the front. It helps stabilize the bike, since just using the fork attachment let's the bike wander all over the bed.
You can also use substitute the D-rings for the bike mount rods and have tie down - and I found the eyelet bolt that locks it to the rails also makes a good tie down point too. Includes a cable lock that threads through the eyelet bolt, but I don't totally trust a cable lock in theft prone Los Angeles. Fine for gas stations though.
Go to Recrac.com for more details, I'll sell mine for $40 plus shipping. It looks like they changed the design for the Tacoma's slightly, but I never had any issues with mine, it worked great.
Here is with the D-Ring substituted. The new design doesn't offer this.