Yes, you can buy them online at domednumbers.com but they only have the larger style 36" i believe. Last I checked they are not capable of making the 16". The original manufacturers of the decals have a lot in stock but magic filed bankruptcy to escape paying for their decals so they wont release them to magic and they cannot sell them themselves due to trademark law. Good luck.
Domednumbers.com are now offering a smaller magic powerboats decal for car windows. I ordered the 15". Not exactly the same as the original decals but still look nice. If you order, be sure to talk to them and tell them exactly what you want. For example I wanted it on a black tinted window so they did a chrome dome decal with a black background.