Y! Green: Imagine the Toyota Prius. Now imagine it stretched a little longer and taller, perhaps a “Baby on Board” sticker attached to the back, and that may just be what’s in store for a new version of the hybrid vehicle. Japanese news source Nikkei is reporting that Toyota will be releasing a Prius minivan sometime next year. The minivan would be the first expansion of the Prius brand by the automaker. Beyond being the first hybrid minivan on the market, the vehicle may also be the …