The Habit-bodied Mercedes-Benz O405Gs are the signature bendy buses of TIBS, now SMRT Buses, for years. The Hispano Habit bodywork was designed by Pininfarina, who is famous for its high-end car designs. Plug doors were fitted on the two exits, and the interior design was also given a makeover. It is the most common type of bendy buses seen on the roads of Singapore, with a total of 208 buses purchased in three batches and was first introduced in June 2000.

O405G Habits were powered by the turbocharged and intercooled Mercedes Benz OM447hLA engine (11,967cc). Some units were fitted with Euro I engines, while the remaining were Euro II engines. They are fitted with either 4-speed ZF 4HP 590 automatic or 3-speed Voith D863.3 automatic transmission. Each bus received EDS that is either from Lawo Luminator Europa (now known as LAWO, of Aluma make) or Transit Media (of TwinVision LeDot make), both of flip-dot LED type that allow for clearer visibility at night. Underfloor air-conditioning was supplied by Konvekta and Hispacold.

This large order of articulated buses, completed in March 2004, marked the heyday of Hispano Carrocera and TIBS. Unfortunately it was the last major purchase transaction between these two companies, and both experienced a turn of fortunes in the following years. Hispano Carrocera and TIBS were eventually renamed as Tata Hispano and SMRT Buses by their respective owners. Due to mounting losses Tata Motors ordered the former's Zaragoza factory to cease production in October 2013, while SMRT Coporation in 2013 faced pressure from shareholders to exit the bus industry until the announcement of a new competitive tendering and revenue model by the government. As the O405G Habits were neither low floor nor low entry, all units were withdrawn by 2020 as Land Transport Authority moved towards achieving a fully wheelchair accessible fleet in Singapore.