Bumper compatible cable to USB & 3.5mm?

I'm searching for a bumper compatible cable that gives a USB and 3.5mm output. I currently have a Monoprice cable that does it, but it doesn't fit in the bumper. I'm using it in my car to both charge and provide audio out to my head unit. I'm attempting to shave down the Monoprice cable, but would rather just find one that works without modification. What would really be ideal is a USB extender cable that provides 3.5mm out as well so I could just use the Apple cable with it. But I can't find that either.