Back in July, Hyundai Motor Group put IU on one of their buses for their 'Bus Concert' campaign. The campaign features famous celebrities holding special guerilla concerts on a random bus. The song she sang on the bus was a special song commissioned by Hyundai titled, "Let's Catch the Bus" and earlier today the song was released on the Bus Concert's official YouTube channel. Check out the special behind the scenes video and the "Let's Catch the Bus" track below! [gallery] [Thanks to everyone who sent this in.]