Having removed, installed, and removed my rear seats multiple times before finally selling them, I can honestly say that I can't imagine them aiding in rigidity one bit, and I certainly never felt such a difference...

For some photos of what it looks like, here is a thread over on MINI2:

http://www.mini2.com/forum/showthrea...deck+hatchback

 

Weight:

"The interior of the Cooper S has now been completely stripped of all door panels, carpeting, headliner and the stereo system. We removed a total of 157 lbs from the Cooper, bringing the weight from 2619 to 2463 (full tank of gas). The weight loss has helped the 0-60 times, dropping them from the low sevens to the mid 6's. Some of that weight will be returning in the form of a welded-in rollcage, which will be built early next week."

http://www.grmotorsports.com/minicoopers.html

Discussion on rear braces on bimmerfest and fold down rear seats effecting it. Apparently, the poster stated that the cars with fold down rear seats have less rigidity then rears seats with fixed seatbacks.

"The E46 with and without fold down seats is what I would base this on (from BMW):
Sedan (w/o folding seats): 18000Nm/deg of torsion
Sedan (w/folding seats): 13000Nm

There seems to be a significant decrease in rigidity by removing the structure to enable fold-down seats. I would venture that ANYTHING put in this space will further reinforce it. How you choose to reinforce it, X it diagonally, across, etc. will vary the amount of rigidity you add, but I would say it adds a whole lot more in the rear (with a wide open hole) than it would in front.

Now if you don't have fold-down seats, I would say the change will probably be small. But on the E46 coupe, which has mandatory fold-downs, I think the improvement should be significant."

http://www.bimmerfest.com/forums/arc...p/t-64927.html

 

Be aware that spare change in your pocket, as well as a full bladder will cause excessive weight transfer.

 

i've seen this post from bimmerfest as well :D

hey, are u being serious or are u kidding?? because when i had my back seats down i can actually hear more rattling from the back of the car, however do u think its becuase the back seat isloated the sound comming from the boot, or is it something else like less rigit??

 

There's one easy way to find out ... buy yourself one of these: http://outmotoring.com/pilo_racing_r...tress_bar.html and see if your car stops creaking. If it does, good ... if it doesn't, remember your car is a lot stiffer ...maybe.

 

do u work for pilo?? :D

 

Nope. I've just been looking into it for future use. I plan on removing the rear seats as I have no use for them and I want to get something to stiffen it up a bit.

 

I had a good long talk with Randy last week, and a very small part of that conversation was about the stiffeness back there. He believes that there is very little more that one can do to make things more rigid; minus the incoroporation of a full roll cage - which he has done

His reasoning is that the ridge separating the lower battery box area from the rear seats is designed quite well. It ties into the rear shock area in such a way that makes it very strong. Seats, up, down or removed are a non-issue for us.

Knowing how Randy has been through our MINI, I'll take his word on this topic.