I really like the wet method of vinyl application. For normal vinyl a couple of drops of soap in a pint or so of distilled water, sprayed into the area for application. You lay the vinyl on top, maneuver it where you want, and squeegee the water out with a soft squeegee. No skill required. It should be good immediately with proper squeegeeing, but it will take about a day or so to dry out to make sure it doesn't move.
Lately I've been using some specialty products as the liquid instead. Rapid Tac and Rapid Tac II (for special adhesives products like reflective vinyl), I found them on amazon, and they seem to work well with no mixing or anything.
I recently did my panniers with a complex cut out in a solid color reflective material, this method can also be used for large single pieces that are printed in a pattern.
I don't know if anyone else has pictures of this one from google images, but I always thought this was a cool wrap job.
That one would have taken time and a heat gun. The painted areas are not exactly smooth, but with some heat, wraps can be manipulated. If you want to try it out, you can get some unprinted vinyl from amazon, and a xacto knife and heatgun (maybe a blow dryer would work) and try it out. I would say judging by my past experiences with wraps, you might be looking at around 400-500$ for a professional wrap of the painted areas depending just because of the complex shapes that it has to be molded to, and they'll want to print the pink color onto colorless vinyl, and laminate it. Of course for something like hot pink, you could do it yourself. Of course your mileage may vary, there is a high degree of variability in this field. Some sign shops charge more than others.
I always thought it would be cool to wrap a GSA tank, because it's huge. But judging from my clark tank on my XT225, gasoline vapors penetrate some plastics, and bubble stickers. Not sure if it's the case with the BMW plastic tanks.