Yeah, it's a lot of work, to say the least. Having made this scheme in the past for the 2013 Daytona car set at SRD, it was a very mixed bag. While it was a good challenge (one that I was satisfied to undergo and come out on the other side), it also more or less turned me off from complex schemes to this very day. (Although burnout also played a pretty big role in that.)
Anyways, here's my advice on how things can be made slightly easier. I'd focus on remaking the graphics the sides first, and then make my way around the rest of the template and work that way. The roof is easy to line-up afterwards, while the front (bottom of the hood on down) is easily the worst and most time-consuming sections. Go with this following layer layout for the colors (top to bottom): Purple, Blue, Yellow, Pink. If you can find a way to paint directly on the body (using 3DCoat or Blender), that will help your workload immensely. If not, then be prepared for tons of tweaking and trial and error.
Finally, here's a bigger pic of the paint scheme layout to help you out.
Good luck!