This hoverboard doesn't have any unlockable upgrades.
Choo Choo is the thirty-fourth limited hoverboard in Subway Surfers. Like any other hoverboard, it protects you from crashing for 30 seconds and needs to recharge before it can be used again. It was released with Subway Surfers World Tour: North Pole. It has the appearance of a train. Like most of others limited hoverboards, it costs 50,000.