If you are thinking about putting in a external amp, and its not a puny amp either (800 - 1200 W), you might be worried about fitting the 4 guage wire. I don't know where other people put theirs throught, but mine fit fine (tight but fine) through the grommet that the hood release cable goes through. it fits under side panels, but if you are going to go for something larger (say 2 or 1 guage) i'd consider bolting it to ground w/ brackets. Also w/ 2 or 1 guage, get something astetically pleasing if the wire is exposed (like Pheonix Gold or StreetWires). AND DON"T FORGET TO PUT A FUSE WITHIN 18 INCHES OF TEH BATTERY)