2008 chevy cobalt

I need guidance on what fuse (passenger side of console) to hook my remote  wire for my amp. The car is a Cobalt LS with the non-Pioneer radio. I would like for the amp to have the same delay function (when the key is turned off) as the radio. Right now , the best I've been able to do is to find a circuit that doesn't have 12v+ all the time, and turns off when the switch is turned off. I pulled the radio and checked the wire harness(switch on, then switch off wait a couple of seconds and open the door) but had no luck there. Thanks in advance."That'll get ya 10 in Leavenworth,11 in Twelveworth, or 5 & 10 in Woolworth". Groucho Marx                                                      

I know the problem you are having. You want to hook up your amp so that it stays powered until the door is opened (just like your stock radio does). But unfortuneately, the stock radio has no ign power wire. It is triggered to turn off and on by a data signal from the car's computer. Theres no way the computer can trigger your amp to turn on. You have two choices to get a RAP (retained accessory power) that stays on till the door is opened. If you have power windows or a power sunroof, they should have a RAP wire powering them. (blue, I think but not sure) or you can simply make your own RAP circuit with a few relays and diodes. There is info on this site under the relay section. Here is pic below of the diagram. The wire that says radio accessory wire, use that to power the remote for your amp (and any other device you want to stay powered till the door is opened, like a dvd player or monitor).

UPDATE       After a little trial and error, I found that by simply changing the amp turn-on wire to a fuse space that says "spare" on the diagram, all my problems were solved. I was trying to have it work by connecting it to a circuit such as door locks or such, but after all of my fumbling around, I tried this and it worked fine."That'll get ya 10 in Leavenworth,11 in Twelveworth, or 5 & 10 in Woolworth". Groucho Marx