If your vehicle interior has a persistent musty / moldy smell, give it a thorough cleaning and then use Griot's Garage Odor Exterminator. The Odor Eliminator works by releasing chlorine dioxide vapor to eliminate biological and chemical odors. On sale, now 50% off!
Purchase here: https://www.autoobsessed.com/products/griots-garage-odor-exterminator-11048