what length power cable is needed in a crew cab?

Just installed my system today. 4 gauge from the battery, through the clutch plate on the firewall down the kick panel and drivers side to the back of the cab along the back wall to the passenger side and still had an extra 3 feet of the 17 in the kit. I highly recommend the type r 12's. Crazy loud. I have to say the fox box was made for them.