Far-Flung Postcards is a weekly series in which NPR's international team shares moments from their lives and work around the world. The moment you board the Onyx bus, the music grabs you. Gospel, Gengetone , Afrobeats — competing at volumes that make conversation pointless. Eight TV screens flash music videos around the cockpit alone. 16 in total. Blue LEDs chase each other across the ceiling. Every surface is painted: footballers, rappers, politicians in wild chromatic detail. I score the front seat, riding for about 30 minutes with Henry Muindi, the owner, from Nairobi's Central Business District out to Dandora in Eastlands. Onyx is new, and currently the most popular bus on the route because of its graffiti, music choice and the young crew. It's very lavish. Outside, a kid spots the bus and shouts. Henry beams. "There is no Nairobi without nganya ," he says, using Swahili slang for these blinged-out vehicles.…