Annoying Rattling, How To Disassemble Dash?

Its a very common issue with tacomas. I believe I read that the problem is the windshield defrost vent that is rattling against the dash.
the best fix imo, and the one that worked for me is.... a rubber fuel-line hose. Its black so it hides itself very well and it fixed the problem for me 100%. I forget what size hose I used but you jam and wedge the hose in between the length of the windshield and the dash. What this does is push down on the dash so it makes contact with this defrost vent and stops it from rattling.
Try it. Its a cheap solution to that annoying rattle.

 

I had your problem as well. I did notice that the rattle wouldn't start until I'd been driving around for a bit. After paying attention for a few days, I realized that when the heat/defrost was on it made something expand in the dash, creating the world's most annoying plastic-ish rattle sound over any uneven surface in the road.

Then I found this: http://www.customtacos.com/forum/showthread.php?t=91251

That cured what ailed me. In a nutshell, you shim the airbag assembly away from the "Reinforcement Bar" (Toyota's name, not mine). This moves the whole assembly far enough away from the dash that no matter how much it expands due to higher temperatures it won't rattle against the plastic.

Worked like a charm for me, and was easy. YMMV. Good luck.

 

This might be related or not...but on couple cold mornings(5am-7am) on the drive to work.Driving around 65mph a sound suddenly started from the driverside corner/windshield. Was a horrible screeching high pitch noise. The first time thought my windshield was going to crack or shatter so I pulled over. Other time just driving and it went away. Hasn't happen again or been loud enough to notice again .