Using large welding cable which by its nature its insulation is thick/heavy duty. Batt neg post to good ground in trunk (down to subframe recommended). Batt positive post directly up front under the carpet to the starter big "batt" lug (no trunk solenoid). A lead from the starter batt lug to the starter relay and from the starter relay to the alt. Power everything up front (switched power) from the batt lug on the starter relay to the ign sw just like normal. Back in the trunk put the on/off switch in either the positive or the neg cable. Use appropriate fuses/circuit breakers as desired (I do not). IF a person uses a trunk solenoid & it is going to be energized all the time get a "continuous duty" unit rather than a common parts house furd solenoid & it'd probably be a good idea to use a continious duty one either way just for longevity. (trunk solenoid aside) Just me, this keeps it simple with the only change being that the batt is now sitting in the trunk rather than sitting up front & there's the longer cable needed to reach it. I dont sweat having the cable under the carpet hot all the time (welding cable insulation is thick) & I do keep it away from any sharp edges that could fray it over time & that is a good use for black electrical tape. EDIT if keeping the ammeter, put the ammeter in series between the starter big "batt" lug and the big "batt" stud on the starter relay that's on the fender/firewall. MORE EDIT If not using a trunk solenoid run a lead (like OE) from the "st" terminal on the ign sw out to the "ign" terminal on the starter relay & a lead from the "sol" terminal on the starter relay down to the small terminal on the starter/solenoid