I work in the motorcycle industry, and know for a fact the HID units are being installed in motocycles as well. There are two main types of installs: 1st) auxillary HID bub, reflector and housings are installed to add additonal light for night time/ off road use, although mostly used on highway. 2nd) low and or highbeam incan bulbs are replaced with HID, in other words HID running when the vehicle is on. The stock incan swap to HID does increace driver visibility at night, such as 4 lanes to the left and right are glaring white.