Is your domain large enough to cover the entire trail? If not, make sure it is. And enable “adaptive domain” so the sim times don’t kill you. Make sure dissipation is turned off to start with, you can enable it later if you want once you have the basic design nailed down. If you’re getting dots/gaps in the trail, increase the “subframes” option on the flow object.
Also, the sim process is the same no matter what renderer you use, and the smoke sim itself hasn’t had much in the way of changes for a couple of versions, so don’t feel like a tutorial made with 2.69 and BI isn’t going to be useful for you.