Or maybe in the Electrical Bay? (I'll move it over there for you) I assume you're running wires into the doors for power windows or locks.
If you're looking for something old looking, use asphalt coated fabric loom
LINK. But if it needs to be flexible, a plastic corrugated loom would likely be better. There's the standard split loom, which might open up as it bends
link, but you might look at the plastic split loom that overlaps on itself
LINK. Then there's the expandable loom (think chinese finger trap)
LINK