Create Your Own Customized/Personalized Rhinestone Car Window Decal. Each monogram letter is approximately 6 inches in height. Detailed application instructions are provided with each order. Please do not hesitate to contact us for information on the application of your car window decal. Rhinestone car decals hold up well to weather and washing when applied correctly and can last months or years, however there are no guarantees as to how long the decal will last. Please understand we are not responsible for replacing mis-applied decals. Also, they can not be removed and reused. Be the first in your area to make your car sparkle!