Agree with above. Let it dry properly, then carefully make small cuts aling some creases and flatten with a bit of solvaset. Not familiar with solvaset myself, I use Micro Sol, whihc tends to wrinkle decals and then it smooths out upon drying.Maybe with the solution under it, plus your "keeping it wet", it simply has to dry for longer? I usually just place decal and go over it with Sol and leave it alone. Once it gets wrinkled, I do not touch it at all.
BTW, missisippivol, just for fun. I've run into one much stronger than anything this will throw at it! Not meant for notmal decals and it's downright scary to use. Tameo solution for tyre decals. I breathe deeply every time before I use it, it really melts decals very quickly. Plenty of first-hand experience...