That spray looks promising. OP, forgive me for asking but, did you try “prepping” the surface, say, wiping the area the sticker is going with something like 97% rubbing alcohol? (Denatured alcohol may be too strong and on plastic acetone would be a huge no-no)
I ask as I’ve had great success in getting stickers to stay on nearly all synthetic materials by first wiping the surface with either denatured alcohol or 97% rubbing alcohol.
Geez, since I have a TRIXX on the way sometime in 2019, I’m going to put the state sticker on it, photograph it with some kind of state stamp and retain that photo. (Point being, I’m not aware of any law in my state that spells out any responsibility of any owner / operator having to go to any other lengths other than affixing the state sticker where the law says to put it. If the state’s registration sticker doesn’t stay attached to the hull (or wherever the state requires it appear), well, I ain’t gettin’ the middle of THAT! :-)
Please let us know what you find works (or doesn’t)!
Ha-ha, or, Just Do This!:
Hey, when you buy the "Spark" registration numbers kit, there is a blank white page in there. Stick the reg sticker to it and cut it out. The reg sticker will adhere to the paper and the Seadoo paper sticks to the spark...... Has worked all season for us so far... good luck....