if the penalty was less, then why would anyone bother testing at all?
Imo due to the nature of the sport, a positive test should result in immediate and indefinite suspension from competition. Failure to test should land a 1 year suspension with a requirement to test at every event you compete in when you come back.
Drag racing is dangerous enough without having some idiot jacked up on something in the other lane. I'm all for people having the right to get high or drink or what ever else they want to do to themselves. But if your sport/business/job requires that you don't, then either don't do it or get another job.