When do you use Meguiar's Paint, Dash and Glass Inside and Out Detailer. The question is more like when shouldn't you use Meguiar's Paint Dash and Glass. This revolutionary spray detailer provides quick and easy cleaning with hydrophobic protection on exterior and interior surfaces. It removes dust, road grim, fingerprints, and bird droppings easily from paint, trim, and glass. As it cleans and protects, it leaves a non-greasy finish behind and provides streak-free cleaning on exterior glass. This versatile detailer is perfect for touch-ups, after hand washing, after taking your car through a tunnel car wash, maintaining a clean vehicle, or as needed for spot cleaning. For exterior surfaces, simply mist onto a section, spread with a premium microfiber towel, and flip your towel to a clean portion to wipe dry. For interior surfaces, spray the product onto a microfiber towel and clean the affected area. Flip the towel to a dry portion and wipe dry. So, whether you're working with paint, plastic, trim, vinyl, leather, glass, or auto screens, this advanced car detailer spray quickly and easily cleans and protects your interior and exterior in just one step.