I want to suggest below pots to save your time in support
1) Create 1
knowledge base for all your components
2) Visit below link for knowledge base or any php script.
freestyle-joomla.com/products/freestyle-...l/fsp-knowledge-base
3) If you consider Vehicle manager component you have to give knowledge base articles for main component as well as all plug-in like How to install it? I will suggest you to check your forum posts & take some posts which posted no of times.
4) If anyone purchased your component (Vehicle manager) your package contain PDF file which is not having sufficient help. I will suggest you to add more help in it.
5) You can take more articles for your knowledge base from your forums.
Vehicle manager component extra feature needed
1) You have to add 1 field in vehicle listing page (backend) E-mail Id . If admin want to add 20 to 30 vehicles for rent & he wants to go all rent request emails to respective owners email Id so this field needed.