i had some trd logos made that are 24 inches wide across my far back windows. they are all black on a stock tinted window, so its jsut a shadow. the only problem is im about to have my windows tinted out darker, so i will have the same guy make another sticker to fit around it and give it the shadow look.
also im using vinals, clear cut sticker material, and im blacking out my a, c, and d pillars on my car so it gives the illusion of one giant window all the way around.