ShaDynasty is a female name, commonly mispronounced “Shady Nasty”.
Also good to know is the following.
Shakotan: a shakotan car, also known as a low down style car, refers to a style of zokusha (gang car).
Dynasty: a sequence of rulers from the same family.
Shady: of doubtful honesty or legality.
Nasty: bad or unpleasant, especially to the senses.
All together now,
ShaDynasty: A Gang of low down cars, of the same ruling family, with dubious intent, assaulting the senses!