Can you name ten things on your present vehicle that make no design sense whatsoever? I'd imagine you can without breaking a sweat, and on something that was designed by human hands. Now take a biological organism, something that thru a process of winner-take-all competition somehow managed to develop into a dominant form: would that form be perfect? Would every piece of the puzzle fit perfectly together in an ordered tapestry? Does the operating system you are currently running still have vestiges of long-unused or obsolete code that do things they were never intended to do but not fatally destroy the final work?
Natural selection does not require perfection. It doesn't even require mediocrity. It only requires that there be something lower on the ladder than you are. But as long as we're asking, what happened to my awesome prehensile tail?