There's NO reason why anyone should have both tail lights out. It takes quite a while for the second to go out and both don't fail at the same time. By the time the second does fail, you should have had an oil change in which the wrench monkeys should have noticed.
Plus it doesn't matter if you have a 3rd LED light that will never burn out, the thing is hard to see + focus on. Next time it won't be a close call and your soccer kids in the back might have a hood ornament to surgically remove
