Studio Unicorn Anime

One hundred miles south of Los Angeles, a reckless biker named Marcia and her newfound acquaintance Noera crash their vehicles after getting caught in the explosion of a semi truck. In the resulting confusion, Marcia manages to sneak off with a briefcase containing a mysterious dark orb. When Marcia and Noera touch it, they experience a vision of Death Valley. Taking this as a sign that the ball needs to be brought to Death Valley, the pair set out on the road, chasing their version of the American Dream, all while evading those who seek to take the elusive object back from them.

(Source: MAL Rewrite)

Mariko is a downtown schoolgirl who loves motorcycles and wants to graduate from the street-racing circle of her friends to the world of pro racing.

(Source: AniDB)