Hm... never heard of Stevia before. I don't use sugar substitutes, so maybe that's why I'm not familiar with it.

FRESCA... omg.... I was so addicted to that stuff when I was first living on my own. I loved it so much! I would drink 6-12 cans a day, and then wonder why I had these horrible migraines. I just can't do the diet drinks.

A friend of my mom's had had diet soda in the car when they went on a trip across country, and I remember she ended up in the hospital because the soda got warm(or hot), and some how changed the chemistry of the soda. She was deathly ill, and they had pictures of her when she basically was looking out over a gorgeous view of mountains and valleys and all that, and then collapsed and fell.

That just scared the bejesus out of me, and I never leave anything in my car anymore that I want to injest. Even if there is some folklore, I still remember what happened to my mom's friend, and just shudder.