I hope the stripes you got were of the highest quality since you paid so much to install them. Some ebay dealers sell cheap vinyl.
humm maybe it's me but stickers, well they're stickers. I've had at least one Mustang in my driveway since I was 16, that was 31 years ago. I swore to myself my current 08GT would be my last and I would NEVER go cheap on it. It's black and I had House of Kolor Burple (Yes Burple) painted on. Then the whole car was clear coated and color sanded. The fellow who painted it, Corey Adams, Hiram Ga disassembled it to paint it, and it is better than I could have imagined. That's just me but I am only doing it once. I paid $1500.00 and believe it was well worth it.