I'm trying to install a 10" sub in a sealed box. i understand i need a line level converter since i am keeping the factory head unit. How would i go about doing this? do i need to take apart the whole dash to get to the wires? and what wires must i splice? also, does anyone have any advice on installing the amp? especially running the power wire from the engine compartment to under the passenger seat. thanks.

 

The line converter is usually done behind the HU. The instructions will tell you what has to be done adn where. I've never done this when i worked at a audio shop so i cant give you that much info about it.
As far as installing the amp, mount it to the back seat (pain in the ***) or make a amp rack out of MDF or even just mount it to the sub box. Just remember to run the RCA cables on the opp side of the power wire. Feel free to e-mail me if you have further questions, i can get into more detail in a email rather then waste more band space.

 

This will tell you how.

http://web2.airmail.net/scutchen/max_faq/