when i put in my steeda springs the rear sat a little higher so i took the rear isolators out and drove a while without them. but then i read all this bs on how they're necessary so i ended up putting urethane isolators in front and back but to be honest i think i'm gonna ditch them in the rear again, it looks like it sits too high. in the next couple of weeks i am gonna put some steeda aluminum control arms in so i think the isolators are gonna be gone when i do that. i really didnt notice a difference with them out, i dont even know why i put them back in to begin with.
i never ran the car without the front isolators but i have run it without them in the rear. i never had any noise. the spring shouldn't move becuse its under pressure
honestly, i think that it's a louder, rougher ride, i wanted the extra 1\2 inch without them but it wasn't worth it. if your only at the track, it's cool, but if you put real milage on it, isolators all day.