I remember when people modified their Volkswagen to enhance the driving experience. What ever happened to Fahrvergnugen? Bags are for kids that grew up watching Pimp My Ride. Turbo is for all of us that enjoy actual motorsport.
I think you might want to check your price point. Folks are selling the same HU @ $350 and under. A new screen is a 130 plus shipping and install/hassle. Perhaps if you dropped your price you'd get more bites.