I don't have a solution for you at this point, however I do have a similar issue which only seems to present itself at highway speeds on textured or rough pavement. Similarly, I could dampen or eliminate the nose by putting pressure on the plastic that covers the steering column. If it continues, I will remove the plastic and see about insulating it.

 

since this seems to happen on only grooved type road surfaces and not every road, perhaps different type of tires could alleviate the nuisance if another solution is not easily determined

 

Its not the issue with Tires, I already replaced tires with most comfortable, soft tires (Yokohama Avid Ascend GT). Ride is butter smooth compared to OEM tires. There will always be some vibration in any car, but issue seems like some resonance frequency matching. If these are damped where panels are touching, I would assume it will kill that buzzing noise.

I saw a video someone opening RAV4 cover, I would assume it would be very similar. May be I will give it a shot. I may also add some dynamat CLD to change the resonance frequency just in case. But I need to get that tape to put at the joints to stop that buzzing.

Also, just wondering if I offended you anyways as I see you did not like post for some reason and gave angry feedback? Let me know what bothered you, I certainly did not meant to offend anyone with my thread.

 

The buzzing noise that occurs on rough or grooved road surfaces appears to be just like the buzzing/feeling of the steering column shaker from the LKA when crossing road lines without a directional. Same? I'm going to switch the setting from buzzer (column shaker) back to the beeping to see if ibuzzing still occurs over the same surfaces

 

No, LKA buzz is distinct, we feel the LKA vibration in the steering wheel. This is just noise, no vibration in the steering. Also, nothing to do with lines, if there some rough texture and typically above 40MPH it will start.

 

First off let me say most techs at most dealers today are useless, IMO. My first suggestion would be go to another dealer and hope your treated better. Next something I have done on other vehicles I have owned that have a squeaky or rattling dash components is to remove that component and put some foam rubber behind it and replace. Always fixed mine issues on other vehicles. I just had similar treatment at my dealer last week. I have 4800 miles on my 21'. Took it in for my free (HAHA) oil change and tire rotation. Was told free oil change was at 10,000 miles. Not on my frigging car. I'll change my own oil and rotate the tires. I hate dealers for anything.

 

You’re better off doing it yourself. The 2.5 engine takes closer to 4.5 quarts of oil rather than the 4.8 that the manual says. I have explained this over and over to service and shown them The Car Nut episode where he talks about this. They continually put in 5 quarts. Doesn’t matter what I say. Finally told them if they do it again I will bring it in and they will have to redo the oil change until they get it right.

 

So literally they are covering 2 oil changes, nothing else. Still looks like they are expecting some sort of inspection every 5k miles/6 months. I don't think any dealer is going to inspect all those listed in there unless there is something obvious hanging under the car. They are not going to put it on lift and check the vehicle like Toyota is expecting.

Oneway I am glad I don't have to deal with the dealer for oil changes. Instead of spending 2-3 hours of time at the dealer and worrying about what they are going to screw up like overfills, forgotten filler caps, left over shop rags on the exhaust and body damages(my first hand experiences), I can do with quality oil under an hour from start to finish(including before and after cleanup).

Seems When Toyota Says 4 services is, only 2 with oil changes and inspection, and other two are just inspection as if dealer is going to spend anytime doing that.

This is what it says from the Brochure:
"1. Covers normal factory-scheduled maintenance for 2 years or 25,000 miles, whichever comes first. Certain models require a different maintenance schedule as described in their Maintenance Guide. Excludes those items listed in the Maintenance Guide under Special/Severe Operating Conditions.
2 Consult the vehicle’s Maintenance Guide for factory-recommended service and intervals. Service requirements and intervals vary by model.
3 Toyota recommends service every 6 months or 5,000 miles. Vehicles serviced based solely on time will receive up to 4 services under the ToyotaCare plan. Certain models require a different maintenance schedule as described in their Maintenance Guide"

 

Finally identified the issue. There are couple of rectangular plastic covers on the steering wheel on both left and right side (not steering column cover). Identified these are somewhat lose and keep buzzing at various speeds. Pressing these down stops. Since dealer did not address the issue, I fixed it my self by removing those cover and applying some foam tape at resting points.
Turn the steering wheel to 90 degrees to left so that the cover comes up towards the Gauge cluster and remove right side cover with think flat screwdriver. Apply foam tape to resting points and put the cover back. Do same for left side also.

 

Chinna. Your post saved the day. I could not for the life of me find the source of the buzzing noise. It's hard to pinpoint since it's intermittent and mostly occurs at highway speeds.

I only noticed that when i pull my steering wheel at the 2 oclock position the noise goes away. I was at my wits end trying all the possible solutions i read online and even some creative solutions on my own, e.g. banging it like the Fonz. Lol

Thanks for your detailed explanation with pics. I have a lexus es300h and the solution worked flawlessly.