If you have a 4ga powerwire from your battery to amps in the trunk and a 4ga ground in the trunk to amps, whats at the battery? Your factory 8/10ga ground. Power starts at the battery (on the ground side technically), adding 4ga in the trunk is useless if it has to pass through 8ga first. It does make a difference.

2000 SVT Contour #1077/2150 MSDS Headers/B&M Shifter/H&R's/

1995 Contour SE V6 #????/Tons KnuProject, awaiting mass mods