For me, it worked by adding a cargo liner and all-weather mats. These are a great start for protection, especially if you are in an area with unpredictable weather.
A solid phone mount or wireless charger is super handy, too. If you are into road trips, you might want to look into a roof or some custom-fit seat covers for added comfort.
What kind of accessories are you leaning towards? Or, at least, thinking about?