This phrase became famous during the episode of, "The Real Housewives of Orange County."
Murrieta Trash can be defined as any White Person With Tattoos in the Temecula Valley, who drives a big lifted truck. This can be male or female. They usually wear Black clothing, black socks and black shoes are the norm. They are known around Temecula and Murrieta as "Bro's and Hoe's." They call everyone "Bro."
Usually a person with a lifted Truck with a logo sticker in the back window, this can be defined as Murrieta Trash.
That chick is Hot. She doesn't appear to be Murrieta Trash.