Son: I want lights
Son: headlights and tail lights
Me: that might sound easy, but I'm betting you want white headlights and red tail lights. There is a problem with that, white LEDs are 3.3 volts, red are 2 volts, are you willing to do the math to design that circuit?
Son: I just want headlights
Me: Good choice, otherwise, everyone would think your dad did all the work.
I didn't tell him that no one would really know that a proper LED circuit would be required, nor that it would all work fine on a 3 volt source, but the whites would be a little dim and the reds would burn out a little fast, but it wouldn't matter in the time it takes to run a few pinewood derby races.
The real hard part would be wiring back to front and to keep it all looking nice!