World 8-Airship (New Super Mario Bros. Wii)
From the Super Mario Wiki
World 8-Airship is the final Airship level and penultimate stage of New Super Mario Bros Wii. Here, Bowser Jr. is fought once again, this time with Bowser's Koopa Clown Car. World 8-Airship is unlocked by clearing either World 8-6 or World 8-7, and its own completion unlocks the final stage of the game, World 8-.
The main enemies on the course are Mechakoopas, but there are also many cannons, whose cannonballs must be avoided. After that, there is a Warp Pipe along with three cannons rotating on a cog. Throughout the level, the player must spin screws in order to progress.
In the end, there is the last battle against Bowser Jr., whose defeat provides access to World 8-, the site of the final showdown against Bowser. During the fight, Bowser Jr. prepares to fight with his broken Junior Clown Car, but uses Bowser's Koopa Clown Car instead. He attacks Mario with fireballs and spiked bombs, which can be used to defeat him by Ground Pounding the ground.