Need Some Help on Car Stereo Questions

I havent had time now but I might give it a shot within the next few hours and see whats up with it. Ill try all the techniques below lol.

Should ANY single layer deck fit into my car or is each deck “specialized” for a certain car? Or is it just wires go right into the deck

I appreciate the offer. If I cant get this damn thing to work I am going to need it