The Big O Tours logo on the side of a coach, as depicted in Grand Theft Auto: San Andreas.
Big O Tours is a coach/bus company operating in the state of State of San Andreas in 1992. The companies slogan is "Sit back & watch us go", which can be seen on the logo on the side of Big O Tours coaches, is a reference to oral sex. The 'Big O' in the company's logo is a reference to an outstretched anus.
They compete with Bikini Line Coach Company and operate the same model of coach/bus.