Lava Mae - the unlikely nonprofit that turns old Muni buses into shower stalls to be used by homeless people - said Tuesday that its second bus is rolling along and that it has a new plan to expand throughout California. Doniece Sandoval, founder of Lava Mae, stood in front of Bus No. 2, which will be parked every Tuesday on Fulton Street next to the Main Library. Sandoval ... had the idea for Lava Mae after seeing a filthy homeless woman crying and saying she would never be clean. Lava Mae's simple solution of providing homeless people with showers and toilets has captured the attention of people around the world, many of whom have asked Sandoval to help them create a similar program. City Librarian Luis Herrera said Lava Mae is a great addition to the Main Library, which sees up to 3,000 visitors every day - many of them homeless and seeking bathrooms, sinks or just a place to rest. Despite all the praise, getting Lava Mae up and running has been much harder than expected, Sandoval said. The first bus is being taken out of rotation for a few weeks so some electrical glitches can be fixed. Finding licensed bus drivers adept at working with homeless people and willing to do it for $16 an hour has also been a huge problem, especially with all the competition from corporate shuttle buses. Sandoval said the bus driver shortage has prompted her to plan for the third Lava Mae vehicle to be a pickup truck pulling a shower stall on wheels. That should be running early next year.