Water spots and streaks can occur if the product is used on a hot surface, so make sure your vehicle is cool, wet and out of direct sunlight when applying this product. If you experience spots or streaks due to using it on a hot surface, you will need to rinse the surface again, and then also use a microfiber towel to buff these off.
Spots and streaks can also occur if too much product is sprayed on, and not rinsed off thoroughly or quickly after applying. If spots occur due to this reason, they can easily be removed simply by rinsing surface off again.
Also, make sure you dry your vehicle like you normally would (drying towel, etc.) after applying product and rinsing off. Letting the vehicle air dry can also cause water spots to form.