rattles when accelerating

2005 Tacoma crew cab. I have been dealing with a rattle every time I accelerate from stop. The noise stops when the truck is traveling but comes back when stopped and accelerates again.
So I have been checking my truck manual and doing visuals by crawling underneath the truck.
I did find one of the four bolts mounted from the end of the drive shaft to the rear differential was loose. I mean finger loose. So took care of that. But still a rattle. So back under the truck again. After grabbing, moving and wiggling things around, I hit the plastic panel that is between the front wheel and the engine compartment. It was missing it's plastic clips that mounts it to the frame. Now the rattle is gone.

 

Heat shields on the catalytic converter. They like to rattle 30% of the time. I just cut a rusty 2008 shield off yesterday.