Junk 4 cyl. coupe,how much can it lose?

I got a junk 4 cyl coupe (i.e dont run,and beat-up) that I got sitting in the backyard.I use some parts off it,but eventualy I want to make it into a bracket race car for the local track.What is everything I can do to get some weigth out of it? Anything goes basicly,lexan windows,cutting floor boards out and replacing with sheets,gutting doors,ect. Anything short of a tube chassis.

Mostly Im concerned with what braces I would need to keep,or I could replace or get rid of.

Hmm,what about floor bracing?

I was thinknig about cutting the trans tunnel out and pop riveting some alum sheets to cover it,no carpet or nothing,just spray can the inside white

Of course it would have a cage I would put in.....

Also,what do you guys think about mini tubing it and going to a ladder bar/coil over set-up? Think it would be more consistant then the factory 4 link style?