Mazda's MX-5-still Miata here unofficially-has always been the paragon of lightweight design. It's never even had so much as a power-operated ragtop. Now, Mazda is going beyond that with a folding metal roof option available this fall. To be called Mazda MX-5 Power Retractable Hard Top in North America, Mazda hasn't announced a price yet, but $30K or so seems likely. Nor has Mazda said how much extra weight the retractable top adds, but we'd guess the car now weighs as much as a {{{Pontiac Solstice}}}/{{{Saturn Sky}}}.