I'm building a rear bumper for my 1999 Ford Ranger Sport after the stock one rusted out. The main section of the bumper is a 4X6 rectangle tube 1/4 wall. The issue I have is that I want to attach the license plate in the original position, in the middle of the bumper. I think it will be prone to damage if it is just attached to the outside of the tube. So, the idea i have is to notch the tube in the middle to have a 2-3" recessed area to keep the plate and the light. I would weld plate in the notched area and probably weld at least a 1/4" plate along the bottom side where the bumper hitch normally was to strengthen the bumper. What do you guys think? Hopefully the pictures will show what i mean.

 

Definately notch it. Without it, it'll likely appear like someone just cobbled something together to get by.

Bear in mind you'll need a way to illuminate the plate, still, so be sure to account for that in your design.