Rewiring stock harness to amp any suggestions?

[BEEMDUB]

So when I first got my charger I took it to get tinted and while I was there I made the grave mistake of letting them install some of my audio and I was like ahh what the hell go ahead and install my h/u and subs, since it was only a small system with a prefab box....Well those degenerate inbred fucks decided that instead of buying the correct harness for my car they would just cut my damn harness at the stock amp..So basically now I have a molex plug with the speaker connections cut at the plug...Its not a problem now because I have them spliced to go to my 4 channel but what should I do if I ever need to go back to stock with my car?