Are there hidden cars in gta v story mode?

Available documentation and reputable sources for GTA V do not list any vehicles that are hidden or otherwise undiscovered within the story mode. Players sometimes report discovering new cars, but these are typically part of the regular vehicle roster or are found during gameplay rather than being intentionally concealed. No official guide, patch note, or developer statement confirms the presence of hidden cars in the main story campaign. Therefore, based on current evidence, there is no confirmed hidden vehicle to be found while playing through story mode.