ok guys i get it...thanks. the install sucks. i could improve it, but why?
Why should you improve it?
For safety.
To keep the car from catching fire.
To keep from killing the radio.
HOW should you improve it?
If its a former interceptor, its going to have power feeds in the rear. Look for them. Look on the internet for interceptor fan sites, they generally have info on where the features are.
Dont run it thru the door jams if you can help it, in fact, never run power wires thru anything that could pinch them. You did good by protecting it with split loom, but even so, dont risk that.
Always fuse power lines as close to the battery as possible. If the line shorts, you want that fuse to blow to prevent any damage to anything.
Remove the paint around that ground point, get a dremel and sand it down to the bare shiny metal. It'll give you a better ground.