considering different responses, we must also notice the rattle differnece between sports seats and journey/X seats and their suspensions accordingly as well, im sure that the sports seat with sports suspension will be more prominent cosidering the suspension is stiffer and the S seats have more moving/adjustable parts(bolsters, thigh extension etc).

And then add the 4was to it and you have the stiffest stock suspension you can get, and still mine is not that bad, i have noticed it about couple of times on real bad rods.

Maybe... but I have no issues with my S seats.

I fixed my passenger seat rattle noise by securely tucking the seat belt receptacle down (forward) to pin it against the seat and stop rattling. Fixed for me. Sounds like your issue is more severe though.

I was at the dealer today talking with a tech. We determined that it was the metal posts of the headrest rattling against the active restraint system. If you punch the side of the seat while sitting in the driver seat you will hear it.

We sat in 5 brand new cars and they all did it. I'm going to try adjusting the seat angle like others have suggested.

The active head restaint is exactly what I suspected was making the rattle in my car. Changing the angle does nothing for me. Its not even the metal posts themselves. The posts slide into female slots, and it is the slot hitting the internals of the active restraint. The only way I see curing the problem is to get inside the seat and put padding between the outside of the female slot, where it touches the active head restraint. my car sounds like doo-doo.

^ do it and post DIY!

I know, I need to. I've been complaining about it in various threads instead. Hopefully one day, but these 70 hour work weeks have left me with zero time to fix.

The problem with mine was the lever to lean the seat forward/back. To get rid of the noise at least I stuck two rubber feet behind the lever so they rested between it and the seat.

i have the same issue! LAME! drives me nuts! taints my exhaust sound!

I had/have the same issue. I found that by switching the headrests, passenger to driver the problem went a way. For now anyway. The passenger head rest in my case was much noiser when nobody was in the seat. By putting it in the driver seat, it doesn't make nosie since I am obviously always in that seat.

I also suspect it might have somethign to do with the load rating of the tires. I had the stock 17" make much less noise than the G37 couple 18 wheels and tires. The 18" have a higher load rating, and a slightly stiffer ride (according to Tire rack anyway). I did notice the rattle more with higher load rated tires. Hope that helps.

I will also play with the seat angle to see what that does, but the noise is all but gone for me.

I have this "problem" too but I thought this would be a physics issue... as in it'd be perfectly normal for a seat that is bolted down to "vibrate" unless it has rubber grommets or any other anti-vibration equipment is used.

It really doesn't bother me because the passengers can't feel it, I don't see it most of the time since I have my eyes on the road. lol.

I don't think we care about how it looks.. it's the sound that drives me crazy. I have A g35x with stock wheels. I tried swapping units with the driver side.... no difference. Sometimes adjusting the seat all the way up helps, but usually not.

I'm at the point where the noises in my car make we want to drive it into a wall just to make them stop.

Vibrating passenger seat? I thought this was another thoughtful feature from Infiniti to please our girlfriends

i'm not sure about the seat vibrating issue, i think you could just attribute it to cutting corners as far as build quality is concerned.

all kinds of vibrations and noises have been my experience with all my Nissans, it's where they lose compared to Hondas and Toyotas

Maybe I've just been lucky, but after 9 years in my Z, 13 years in my maxima and 11 months in my G...nothing but good vibrations