While it is possible to apply Rain-x to the windshield of a motorcycle, it is important to note that it may not be the best option. This is because the high winds and speeds experienced on a motorcycle can cause the Rain-x to be removed more quickly. Additionally, the application of Rain-x can make it more difficult to see in low light conditions.
For these reasons, it is generally recommended to use a dedicated motorcycle windshield cleaner and sealant. These products are designed to withstand the rigors of motorcycle riding and provide better visibility in all conditions.