Hmmm! no answers yet. Well I'm no authority on Bowser shells or any of the newer shells available today.
Stephen perhaps no one has stripped a new Bowser shell. what I would do in this case is remove the shell find an area underneath that has thick plastic. I would then put a drop of the alcohol on it and watch for a reaction. If none then it's likely safe to use your plastic shell. Note where all the little detail pieces go because it may be possible for the alcohol to loosen them. In your place I would go with the Alcohol, after all it comes in a plastic bottle.
I use brake fluid, I use it sparingly. I do not soak the shells in a bath, I brush in on the painted areas only, then remove the paint with a stiff tooth brush as it softens. Brake fluid can craze the plastic, can make it brittle and usless. If you go with brake fluid go slow and carefully.
Good luck
Cheers
Willis