The best level to get this achievement on is the hovercraft sequence in "Never Kill Me Again." You're driving on snow and ice and the hovercraft slips and slides really well, making it ideal for drifts and powerslides; it moves around like a pat of butter in a hot frying pan, making it easy to do long drifts on this stage.
Simply take every opportunity you can to throw in a drift or a slide on this level (which is fairly long and has a few tight corners that you can do big drifts around) and you should get the 500th drift point right near the end of the stage.