I guess you will have to the car company this question. I know this is not much help so sorry about that.
Take the door panel off. Match the Wires.
Try changing the ignition wires
Normal car radio is no different than aftermarket. Determine the output wires on the radio, take them into the amp and the output from the amp back to the wires going to the speakers. Normal car speakers are not going to take the output of the amp if you raise it much.
And that is three more screws than are necessary to consider it "attached". In fact, if it were just laying on the floorboard with wires to the stereo and speakers it would be attached.
Nope.
The wires are probably getting too hot.
check in the trunk as the wires are exposed and luggage can very easily shift them so that they short out. This happened to my nephew who as a 2000 ECHO
Read the sides. Put inputs left and right in the correct slots. you can get input from speaker wire coming from speakers already in your car that is hooked in to the radio or amp. Then run wires to the speakers
there is 2 wires one should be red to alarm and black to ground.
try changing plugs and wires
You take the stereo out of the car, get a 12v battery and charger, or a 12v regulated power supply capable of about 5Amps. Plug the red and yellow wires to the positive supply and the black wire to the negative. The speaker wires are in pairs, some stereos have four speakers. There may be extra wires for ancillary use, orange for illumination and blue for electric antenna. These may be ignored and insulated.
On my Pug 206 I had speaker terminations for rear speakers but no rear speakers fitted. I simply chocolate blocked each one to extend the speaker wires to the boot of the car. Even if you have rear speakers fitted it should still be possible. I've got a 3dr car, so it was fairly easy. If you have a 5dr you may have to try and remove fittiings to run the wires properly