dont remove it if you dont have to! ask WDE_BDY! he'll tell you how much of a mission it it i got mine sand blasted.
and yes, it is the rubbery black rubbery stuff, its not that heavy man. used about 1L so far, and that got me the inside of the doors, front guards and 1/4 of the underbody. so 2-3 liters will do everything i want to do. weighs bugger all, if i was that worried about the weight of the car, i'd lose some weight myself.