I think the overall idea of shrink-wrapping is good while the actual end-result is bad. Here is why:
Shrink-wrapping is an annual event. Every year you get to spend big bucks to make your boat virtually unservicable. Furthermore, these covers are usually too thin to sustain strong winds and/or debris. I''d go with something stronger that will last the years and allow you to work on the boat.
We built a wooden frame on our topsides that support a nearly impermeable cloth cover. This cathedral shaped frame sheds snow and we can remove it in two days every spring. The zippers in it allow easy access to the boat during the winter for maintenance chores, etc. and the cover also provides shade in the summer. If you are planning on keeping the boat for any length of time, this is a much sounder investment.
Check it out at vonwentzel.net. Follow the link to Prout and then on to the Exterior section.