Mishimoto 2013+ Ford Focus ST/2016+ Focus RS Aluminum Expansion Tank - Wrinkle BlueAdd some reliability and engine bay styling to your Focus RS ST with the Mishimoto RS ST expansion tank. This tank features internal baffles to prevent coolant starvation from overflow ports on the engine. Also, during high speed cornering, braking, and acceleration, the internal baffles reduce coolant sloshing. The engineers at Mishimoto have included a sight tube to allow for proper observation of hot and cold coolant levels, making engine