The Girl in the Green Silk Gown:

The Girl in the Green Silk Gown: Book 2 of The Ghost Roads by: Seanan McGuire
Fiction: Paranormal, 331 pages
Physical Book Count: 31
Book Count: 65

I didn't notice that this was book 2 in the series until I started the book; however, all the important things that you need to know for this story are in the book.  This book is a story of Rose Marshall, aka. the Phantom Prom Date, aka the Girl in the Green Silk Gown, a hitchhiking ghost who was killed on the way to her prom.  This book takes the stories of the Phantom Prom Date and adds another layer to it.  For she was killed by Bobby Cross, a former actor who made a cross roads deal to stay young and alive forever.  But for him to do it, he must constantly drive in his car, that is fueled by the people he murders with it.  Rose was one of the 1st people he killed in the 1950's and the only one who got away.  So of course, he will do anything to destroy her once and for all.
In her decades as a hitchhiking ghost she has made many friends including: Emma, a Bean Sidhe (banshee), Apple, queen of the North American routewitches, Gary, her prom date from that fateful night who lived a long life, but managed to turn himself into a ghost car, and the Ocean Lady, a early American road that has been traveled enough that it has become a goddess of twilight.