This hoverboard doesn't have any unlockable upgrades.
Rudy is the twenty-fourth limited hoverboard in Subway Surfers. Like any other hoverboard, it protects you from crashing for 30 seconds. It can only be unlocked by collecting 40 (little Christmas trees) during week 2 & 3 at the London 2014 Weekly Hunt. Like any other hoverboard, it protects your character from any obstacles for 30 seconds. When crashed, it will explode and need a few seconds to recharge before it can be used again. It has the form of a reindeer. It was first released and had its only appearance in the London 2014 edition.