8 speaker celica head unit upgrade help!!! Options

[chris32880]

Hey guys I upgraded my speakers with pioneers, 1 inch tweeters are still stock, the 4 inch top speaker on door are pioneers, 6.5 in back are pioneers. I just ordered 8 inch 400 or 450 watt 8 inch speakers, the speakers weren't a problem at all, now I want to do a double din pioneer head unit, I need to know if I have to buy the plastic for it to go in like a single head unit needs... The celica 8 speaker runs on 2 amps, I found the metra adaptor for the amps to be used te double din head unit I will be using has 2 RCA plugs the adaptor has 4 I need all 8 speakers to work so I need install help I found a forum with info but want to wire everything perfectly and need to know if the head unit I'm buying has 2 and the adaptor has four if it will work or not thanks any feedback will help

[chris32880]

I wired my 8 inch today here's the bad all my speakers are running on 1 amp, tried connection to second amp for 8 inch and bam no sound so I had to tie my 8 and 4 inches together and the power them to one amp, so my question now is if I buy a aftermarket amp to replace my factory amp will it work? I can then run subs and ect and won't need the metra 70-8112 even though its on way in mail... I was like wtf!!!