My $500 '69 Valiant

At the top of the page, there is a tab labeled "Thread Tools" If you click it, it drops down a few more choices. One of them is "Subscribe to this thread". When you do that you can keep tabs on this thread.
OR I think if you just comment on a thread it automatically subscribes you.
Either way, when you go to your user panel (where your private messages are) you can look on the left side of your messages and there is a link to "View subscribed threads" if you click it, it will show you all the threads you are subscribed to and the ones that have new comments will be in bold letters.
I keep track of all the interesting (to me) threads that way. Yours is one of them!