Crash into Me by Albert Borris

Four suicidal teens meet online. Jin-Ae is a lesbian who is not out to her Korean family. Owen doesn't believe anyone would really care if he dies, but he'd still like to make his death look like an accident so that no one would feel guilty. Frank doesn't think he can live up to anyone's expectations, especially his father's. Audrey, a compulsive liar, had her heart broken when her last boyfriend dumped her and so she jumped off a roof. They form a pact to commit suicide together, and head off on a road trip across the USA, stopping along the way to visit the graves of famous suicides. Final destination: Death Valley in California.