The frequency of changing Bath and Body Works car scents may vary depending on personal preference and the strength of the fragrance itself. On average, people tend to change these scents every three to four weeks for optimal performance. However, if you prefer a more subtle aroma or notice that the scent is fading quickly, you might choose to change it less often. Ultimately, monitoring your own satisfaction with its fragrance level will help determine how frequently you should replace your Bath and Body Works car scents.