I've cut vinyl stripes for cars before. It is quick and easy and like SprayTech said you can reverse your decision if you don't like it. Iv'e cut them for ElCaminos and Chevelles. It woud take a little set up to get the measurments for a Mustang (i.e. Chevelle stripes tapper to the front with radiused outter corners on the front, etc.). If you decide to paint you can also get the stripe cut out in reverse in (Paint Mask Vinyl) so theres no tape seams @ the corners and minimal measuring. Mask vinyl goes down it 1 pc. but doesn't have the aggressive adhesive of standard vinyl so it peals of as easy as masking tape.