First off, thanks for reading this thread and any help is appreciated.

I have a 2003 Dodge Dakota Quad Cab and purchased a Kenwood Powered Sub KSC-SW1.

I have decided to place it under the front passenger seat and splice it through the front right speaker to power it.
How do I feed the wire into my door safely without risking damage? Where can I find an opening to feed through the firewall so I can ground and get power for the sub?

Thanks again for any help!