J_Cor wrote:systems are actually pretty easy, unless you want your car completely stupid loud or are looking for a different display screen a new head unit will not be necessary, I suggest that you go on crutchfield.com for a sub, amp, and wiring harness. I actually have a 1000 watt kenwood amp in that i just took out of my truck before buying my altima (a month ago)...if you are interested in it, which 1000 w is more than enough for almost any system youll fit in an altima, PM me ill sell you the s*** dirt cheap ($40ish ?) id actually love for you to take it off my hands, boost my springs fund

, anyway...crutchfield.com obviously JL subs are nice, I had an alpine type R which sounded extremely clean, even in my old tin can explorer! good luck keep us posted!
Not trying to be a d!ck, but I disagree with everything you just wrote.
An aftermarket headunit should be the first audio upgrade you make, before you even think about replacing speakers or amping anything. Aftermarket headunits allow so much more control over sound and 9/10 times will boost power right from the get go. If you arent going for loud, then you are going for quality right?
Dont ever buy a thing from Crutchfield unless you cant find it anywhere else. They are stupid expensive. I will say that Ive purchased a few odds and ends from them and their customer service is always great. They are good for research and reviews, thats about it. A better price is always to be had unless its clear our inventory time.
I also dont understand how you can argue that stupid loud isnt a necessity but are selling a 1,000W amp? Again, not trying to be d!ck, just trying to understand your logic.