Alex at Scooter Gallery told me that the 250 would retrofit onto the 150 frame. With gas prices the way they are, I´m sure that we will be seeing many mre fuel effecient vehiciles of all sorts. I have been watching Zap in Calif. work toward bring the Smart car to America)
I also read that in Europe, the Velux has optional, detachable side covers, but that the DOT considers them illegeal in the US. I had thought of making some myself & see if the DOT would notice.