I do not know who you saw set up the amps thru the factory fuse box but I would highly not suggest that! Begin under the hood by setting a fuse block. Should be within 18" max from the battery. Normally there is a good solid location to mount this. If it is a simple in-line fuse and not a mountable type disregard that. Find a grommet or something going thru the firewall already and run the power wire thru there. Inside the car now run the wire back to the amp location. Back under hood tie and cut the wire and connect it to the fuse block or in-line fuse holder, leaving the fuse OUT of the holder, then to the positive side on the battery terminal. If you purchase a good amp wiring kit it should have terminal leads and everything you need to run the install. You can also purchase each item separately. You need a good guage wire for the main power, fuse block, battery terminal connectors, terminal connectors for the ground wire near the amp and that should mostly cover you. Any issues or questions you have feel free to drop another line.