Its a good idea to do a simple interior and exterior maintenance at least once every 2-3 weeks. Interior of a vehicle accumulate a lot of dust and germs over time. Interior detail is first of all is about making sure that the space where you spend hours of your life is clean and only after that protected from elements. Exterior of a vehicle we like to compare to a suit that we daily drivers wear every day and how this suit looks depends on us. Lots of time we see fairly new vehicle with rust spots, swirl marks, dull paint etc., all of that is a lack of simple maintenance. Bird droppings, tree sap, bugs, road salt in a winter, even rain will affect the look of our vehicle. Over time those and other factors will damage our clear coat. Simple wash and rinse for exterior, vacuum and wipe down for interior will help to maintain vehicle clean and you healthy.