I know this is weird, bizarre and dangerous but, I love the smell of car tires! This is a non-visual birthmark my Ma gave me. When she was pregnant with me she had awful morning sickness, so she would go into tire shops and inhale the rubber smell to relieve her of nausea. Til this day, I buy bicycle tires to smell them and sometimes chew on them.. Go ahead and judge, but ladies please be mindful of what you do while pregnant. It can effect your baby for life! I really need to seek a shrink for this!