This may not be the fix you are looking for... but it has kept our 05 rattle-free for the past 4 years.
After checking that all of the hinge bolts were tight... I looked at the auto parts stores for rubber isolator blocks, but could find none.
I ended up using the right size corks from the hardware dept at Lowes... placed upright & pushed down on the head of the rear fender bolt when the hood is open. The bolt head will cut into the cork & hold them in place (or use a spot of silicone caulk).
A few weeks ago the rattle returned... the cork had compressed after 3 years & needed replacement... I put a spot of silicone grease on the front rubber hood isolator blocks for good meausre.
Give this a try... it is a cheap fix that cured my hood rattle.
Just as a side note... I also found that over the winter the zip strip that isolated the rattle of my e brake cable had broken & needed replaced.
the hinge bolt might seem tight, but you still have to replace it. they threaded the bolt too short. it is tight but it isnt actually clamping the hinge to the hood.....dealer will do it for free if still warrentied....or you can take it out and add a thin washer to make up some of the play.
I had the same rattle in my 2006 Canyon hood. Took me forever to find it. The rattle seemed to be coming from under the dash. The result is that the hood hinge bolt is partially threaded and the blank over sized portion of the bolt bottomed out before the hinge tightened. Attempting to tighten obviously stripped the threads. I managed to get a lock washer and nut on the protruding portion of the bolt and tightened it to the point where the rattle was gone. So far it seems to be a permanent fix. Nice to have the rattle gone... great little truck though!