To do hillclimb or sprint isn't any different... As I understand it, you can simply pay for an MSA license, comply with a few scrutineering rules, then race up a hill.
To my mind this is a 'good thing', a liberty to be cherished. Any sport needs to have a broad range of entrances. For a local drift event, the barriers to participating should be low, but the D1GB championship, for instance, has a well monitored licensing process:
http://www.driftworks.com/index.php?...s&articleId=15