Aaahh, that's another story. Most of this kit you can use for a trunk mount, with the exception of the battery to box cable. You'd run your 1 gage cables to the engine bay, then tie into the junction box with the positive cable, and ground to the engine block with negative cable. Should require around 14 ft. of each, available at a welding shop.
I've seen as many people run 4ga and get away with it as I have seen people run 4ga and get burnt. 2ga would suffice...1/0 ga is overkill but it's actually cheaper sometimes compared to 2ga (if you are looking at good wire and not welding leads).
1. Install a Ford remote starter solenoid in the tunk.
2. Ground the battery to the rear frame.
3. Ground the engine to the front frame.
4. Install a longer purple wire and connect it to the solenoid
to activate the solenoid.
5. Bridge the two terminals on the starter together.
6. Install the heavy gauge 1/0 wire from the solenoid to the starter.
7. Cut the fusible links and solder longer leads to reach the "HOT" side of the solenoid. :
8. Install new lead from alternator to the "HOT" lead on the solenoid.