About to run 4 ga power wire from batt to trunk. Which side is the best to run it down passenger or driver? What side did you all generally run yours down?

 

i ran mine down the passenger side because there were less wires there already

 

I ran it down driver's side b/c that's the side where the battery is. It doesn't really matter too much IMO. Just remember: the great gaping hole in the inner fender by the battery leads to a brilliant place to route the power wire: inside the fender. Pull the plastic liner in the wheel well for access. As someone who has routed wires through the firewall as well as the fender, trust me: the fender is the easy way.