Well, I have finally replaced driver side lower control arm today (took 4hours). I have noticed the stock(I am not sure if the prev owner replaced it) lower control arm was aluminum not steel. I got the steel once from Zygmunt. It was just pain to take the old one off. Do I need to replace it in pairs even if the passenger side is absolutely perfect condition? I am thinking I might have to since it is now aluminum and steel on either side. I would like some help on this. Thank you so much for your input in advance.