Alright, I'm not that knowledgeable about car stereos, so forgive me if this is a not a good question.

My maxima came with six speakers (four 6.5's and two tweeters). But I noticed that all the aftermarket head units say something like "4 x 50W". Does that mean that when the head unit is harnessed and installed, only four speakers will be receiving power? I already have an amp and a woofer in the trunk... But I want to make sure that my tweeters will be used when I get the head unit. Does that mean that I will have to manually split wires so that my tweeters will receive power or will the harness automatically do that?

Also, do you guys know of any good black double-din head units (preferably with MP3) that would match my black/grey interior?

 

yes the new headunit will power all 6 speakers, no problem there as for as a good double din headunit i would kinda steer away from that if you really want good sound. go with a head unit that has 3 sets of rca's, there's a big difference in clarity. but if you really want to go with the double head unit look do what i did. i have a kenwood excelon kdc x717 with 3 sets of rca's and went off and got a slave kenwood cd player kdc d300, it'll give you the double din look and you'll have 2 cd players.