My MINI has been fairly rattle-free, but a few weeks ago it developed a rattle in the rear seat area behind the driver's seat. It coincided with a cold weather snap, so I chalked it up to the weather.
The rattle continued, so I climbed in the back seat to see what might be the cause, and I found that the outboard rear cupholder had come loose. It's apparently installed by inserting into the hole in the armrest, and twisting about a quarter turn. Mine was simply loose, and I inserted it, twisted it to lock it in, end of rattle!

 

had the same problem and it drove me crazy. My 5 year old son fixed the problem for me

 

Good to know - and geoffv, get your son into MENSA!

 

I hope this is an easy fix for my rattle as well - gonna try it tomorrow! Thx for the info.

 

My 2 year old figured out this method to remove the cup holder when he's bored. Most of my rattles now stem from his methodical disassembly of all interior bits he can reach.

 

My driver's side door lock rattles (the little nub, not the switch. . .does that make sense?). Drives me nuts.

 

I had the same thing with the cupholder. I noticed it the first week I had the car.

 

I have a squeak rather than a rattle coming from the same area. I'll have to cross my fingers its the cupholder when I check tomorrow.

 

The squeak comes from the seat latch mechanism. A little WD40 or white lithium grease on the latch in the seat back should eliminate the noises.

 

Anyone tried a plastic-safe threadlock on the cupholder to keep it from loosening?

 

I'll be sure to have some grease in hand when I take a look at it! Thanks so much! Freaking squeak can be heard even when my stereo is on full blast!

 

I've had a similar "squeek" coming from the back seat area but it's intermittent. I hope lubing the latch fixes the problem as well!