Afraid that treating their next head cold could lead to suspension, drivers are demanding that NASCAR provide a list of banned substances following Jeremy Mayfield's suspension for violating NASCAR's murky drug policy. Mayfield claims the positive test was a result of prescribed and over-the-counter medicines mixing together.

Said driver Brian Vickers, "To be honest with you, I'm a little scared. I'm afraid to take Nyquil. If I get a cold I don't know what to take. To me this is extremely gray, extremely vague."

UPDATE: Chairman Brian France said NASCAR will not reveal what substance Mayfield was caught using in a random drug test May 1.

In light of Mayfield, drivers want list (ESPN)