Mapmaker: Red, Green, Blue, and WOLFEN - The Mapmaker Series from the Gewellyn Chronicles

Tessa Chart, the Mapmaker, has long, beautiful red hair. So does Abilynn, High Princess of the Elves. When Wolfen, super-werewolves attack the Fairy Circles, the Blue Fairies turn to the Princess for help. But when they mistake the mapmaker for the princess who was raised by the Wolf King, Cormac Mac Art, it could spell doom for the Blue Fae. They risk ire of the Leprechaun Queen Fillian who rules over the green and blue wee folk alike.
It will take a headlong dash across Ireland in Abilynn's Stutz Bearcat and a Rolling Royce (or something like that), with help from a Drow elf, an assassin-turned-spy, and the Wolf King himself, if they hope to turn the tide and send the Wolfen back where they belong. Then there is the ever-watchful eye of Fiona, the High Queen of the Magical Folk of Ireland and the Aerielands, the most powerful elf in the entire Nine Worlds, and Princess Abilynn's mother.
What's a Princess to do?