I would like if someone could make driveable cars, Like the plane mod, but for bukkit and not so laggy...
This is a mod, not combatible with Bukkit. Please wait until they announce mods to be compatible with bukkit.
What he meant is that you need to mod the minecraft client and the server (craftbukkit.jar). Therefore it is not a plugin but a mod. As of now this is not possible without changing the bukkit code and re-building.