Bicycle decorated with LED lights.
This is Eric Severn's big blinky 36" bicycle.
LED lights seem to have supplanted el-wire on the playa, now that very bright ribbons of color-morphing LEDs (with a controller) have become widely available and relatively cheap. Those LED ribbons are much brighter than el-wire.
Photo taken at the Burning Man 2015 festival (Black Rock Desert, Nevada).