Just removing the rear seats, spare, jack, rear carpet (3 peices), and a couple other things back there you'll remove over 100lbs. I'd have to look at my weight sheet and add stuff up for 'easy' things.. The front seats are actually quite heavy and if you can remove the passenger side one that's good for a few more pounds (I haven't weighed them yet, but they are heavy) it's just two bolts.. If you want to goto the extremes I am the airbag stuff can be removed along with several other under dash items and if you don't mind not having carpet all of the carpeting.
If you guys want I'll do a write up on weight reduction for the RLs..I can show you where bolts are and everything even though all of my stuff is removed..I can still show you the areas and, if I get the time, include weight with each item as well.
I can tell you for mine I'm going;
Rear seats
All carpeting (put front floormats back in)
stock front seats
I'm keeping my center console because I like my cup holder...

A bunch of under dash stuff
Stereo and all related speakers AND wiring
airbag system and all related wiring
spare
jack
all stock restraint system
replacing the trunk/hood/roof with carbon fiber
new steering wheel after airbag system removed
relocating cruise control to on-dash
most of the vent system
air conditioning and related items
IF I can get away with it the EVAP stuff (I've removed it on my bike.)
wheels
all glass
gutting the doors and we'll be removing metal from the car as well..
IN place of stuff:
Sparco seats
4pt harnesses
chromoly roll cage/harness bar
new quick attach steering wheel
lighter weight wheels
lexan windows
There's a few other odds and ends things I'm planning on doing and working on measurements for. I'm waiting for a company to get the carbon fiber trunks done and for them to get us a picture of the product before I commit to one. The roof I'm going to have someone one-off for me..