2. Wax Tarts... You can find them at Walmart or even specialty stores such as Yankee Candle. Pfullace the tart in your cup holder. Be mindful of the area you leave in...the wax may melt in the summer.
3. Tissue paper and fresh herbs... Place the fresh herbs in the tissue paper and place under the seats. As the herbs dry the more you will smell.
4. Essential oils. You can either shake a few drops on your car mats or shake some drops on those old tree fresheners and place under the seat.
If these work for you, let me know.
SOURCES: Real Simple, Apartment Therapy, Crunchybetty.com, theresaann.com, and Readers Digest