Downpour — S.E. Schenkel

A car is found neatly parked on the side of the road. A short time later, the spot is marked by a cross. Tapp and team are hired to find the missing driver, a middle-aged, Michigan woman. The investigation leads to similar cases where women vanish while on the road, and crosses appear shortly afterward. Where are these women? And what is the meaning of this common thread of car and cross?