Unfortunately no one guessed why my tires went flat. However, I am going to give everyone that participated my main idea activity. I appreciate everyone's support.
Front Tires: Tires come with barcode stickers that often fall right where the tires seal. Occasionally, the sticker actually prevents the seal from being perfectly sealed. Whenever I parked my car with the sticker towards the ground, the seal broke and let the air out.
Back Tire: A key punctured it.