Stripe Longevity

I got my vinyl ones put on within a week of getting the car. They still look good for the most part but they have started to 'chip' or wear differently than the paint has. If I had the option of doing it again, I'd paint them on. My .02.

Paint is costly, though, and permanent.
Decals can be removed and even replaced for a fraction of the cost of paint.
My two cents.

I know in the days past...stipes and graphics from the factory didn't last too long but I think they've improved somewhat. When I bought my 2004 f-150 with 4x4 stickers on the back of the bed...I nearly removed them for fear that one day they would turn into that yellow-crackly peeling things I saw on the hood of my uncle's Trans-Am when I was yonger. However, I ended up leaving my 4x4 stickers on the bed and it's now 7 years later and they still look like new. Not sure how the stipe kits go for the Mustangs...but they'll probably be decent quality. And like stanmckinney said...they come off if you get tired of them or if they do start looking crappy.