depends how quiet you want it to be, but if your gonna put a proper carpet with under lay even, i wouldnt bother replacing them, just get a good paint that will resist rust, dont use the "tar" paint though it seems all good until 2 mnths or even 12mnths later when you realise it still hasnt dried, it just sticks to everything, thankfully my mate did it to his gemini before i did it to my car