Well currently it is in the way of my CAI, its not the oem and its big and bulky. Its almost always empty, i've never seen it fill. Do I even need it? Its a 88 gt.
I wouldnt say its necessary but if you dont want to check your fluid level all the time i would keep it. someone makes a small unit that can mount near your battery between the ac compressor/ PS pump and the radiator ill see if i can find it for ya and ill post it up.
your coolant needs to expand into something then it will suck it back up while is cools down.