Hows this sound?
Hmmm, so all moonroofs are sunroofs, yet not all sunroofs are moonroofs? I found further clarification -- "sunroof" is the term originally used to describe a metal panel that would only allow light or air in when opened. A "moonroof," on the other hand, is a glass panel that can allow light in even when it is closed (provided, of course, you slide back that nifty fabric-covered panel to expose the glass).
True sunroofs, those made just of metal, appear to have gone the way of 8-tracks in automobiles, and these days, most "sunroofs" are really "moonroofs" -- panels of tempered glass, usually tinted, that tilt up to allow a flow of air, or slide back into the roof entirely, giving the car occupants a brief but tantalizing glimpse of life in a convertible.