I was detailing my 2005 white prius. The first day I washed it, clayed it, used Meguiar's Ultimate Compound in a few spots, washed it, and polished it. The next day I got ready to wax it and noticed there are tiny little bumpy flakes all over the panels that I can flake off with my fingernail. What I do is take them off the paint, wax it, and they seem to not come back. But I'll have to watch for a while to see what happens. Does anyone know what these are?

Duno... might be a previous wax or sealer that was used on the car.

Looks like it was repainted and the flake is actually dust trapped inside the paint.
If you can pick it off and its still white, most likely dust got onto the car after the first color coat... Only if it was repainted.