The key for this achievement is finding the right song. With proper practice you should get better at drifts in no time, but most songs won't have long enough curves to make a drift that lasts long enough. Usually more intense songs should have more curves, but I have seen slower ones with longer curves as well (although with a lesser number of total curves). Some songs where I've done drifts of more than 16 beats were:
Tension Head by Queens of the Stone Age
Dismantle Me by The Distillers
Excuse Me Mr. by No Doubt
Neon Tiger by The Killers
The Blood That Moves The Body by a-ha (example of slower song)
And many others.
I made a video of a 31 beat drift in the song Deer Dance by System of a Down