Quote: I seriously doubt undercoating would be applied to a partially assembled car.My 70 Hemi runner has undercoating on both ends of the side marker light plugs including a lot of the exposed under body wiring.
70 roadrunners don't even have a front valance to get in the way of bumper installation, etc. So that's probably Not a very good comparison. Still, it's an example of the turn signals being connected during undercoating. (It doesn't prove they were installed in the bumper during undercoating, they could have been dangling.) However, that roadrunner info may not apply at all to Challengers.
