Rear Tire Noise

For those who already read this, I'm sorry, I originally posted it to the wrong section.

I just purchased a new Tacoma (Access Cab, TRD Sport, V6, Auto). I owned a Tundra since 2001 and liked it very much. I upgraded to the Taco for new technology and better gas mileage.
I'm hearing a high frequency noise from the rear of the truck which I'm relating to the tires because it changes with different road surfaces and different speeds. The tires are Bridgestone Duelers which are suppose to be relatively quiet. I've had it back to the dealer twice and they couldn't find anything mechanical wrong and said that was just the sound these trucks make. There's no vibration, just a high pitched tire sound.
I'm wondering if the composite bed could be amplifying the otherwise quieter road sounds. My Tundra (steel bed and bedliner) was very quiet.
Does anyone have an opinion or have experience with this type of noise. I don't hear any noise from the front tires. Are Tacomas just noisy in the rear? Will different tires help or maybe a bed cover?
Thanks, Rick

 

may be the tread of the tires...

 

I hear my rear tires alot too(BFG a/t). I just accept it , oh and turn the radio up

 

Thanks Phantom. Each tire had 35psi, sticker calls for 29psi. I reduced the pressure and it seems to have helped. I still hear some noise, but it is lower and its pitch much more acceptable.

I'm glad I corrected the pressure before the tires developed uneven tread wear.

I've read some people's complaints that these tires wear out prematurely on Tacomas. If Toyota consistently overinflated four tires on my truck maybe they overinflated thousands on many of their trucks.

I like my truck a lot more tonight.

 

I already did the extra D-rings. I found this forum while searching for help in wiring my trailer brake controller to the plug which Toyota provided. I found Maverick491's excellent instructions on doing it and noticed that he also posted instructions and photos on installing forward D-rings.

http://www.tacomaworld.com/forum/2nd-gen-tacomas/2269-bed-tie-downs.html#post17434

I followed his lead on purchasing them from toyotapartspeople.com. The total was $29. Not as cheap as you posted, but cheaper than I could have got them from the dealer.

Those nonexistent D-rings were one of the first things I noticed missing when I got the truck. Next was a non-locking gas cap. I just ordered a Stant 10504 locking cap. According to Stant, Toyota used this screw type cap a few years ago, went to a push-in cap in 2008 and back to the screw type in 2009. So I hope it fits and that it works in terms of the emission system. I'm more concerned with vandals putting something in my tank then the threat of gas being syphoned.