Generally applicable to women (although men are not excluded) who are known to freak out, act tryannical, snap for any reason, and otherwise turn "bitchy" due to hormones or disposition. During said rampages one can be described as "riding one's bitch mobile".
Employee: Brad is lurking in the back room reading D&D books again...
Manager: I guess I need to jump on my bitch mobile and go "motivate" him.
Sibling #1: Mom's asked me 3 times if you have taken the trash out yet...
Sibling #2: Yeah, she's riding her bitch mobile today. I'm laying low until she calms down.