They usually follow a similar pattern. They will post an unusually long message which goes into great detail about a car which they have purchased (or are about to purchase) and then they've discovered that there is something dodgy about the mileage or its history.
Then they sit back and watch the comments, and never post another message on the subject.
Good example recently.....the Honda civic thread about the vehicle in question being clocked. Masses of detail; never heard from the OP again.
Apart from anything else, it's nice to have the 'conclusion' or the 'fix' reported for others that might be searching for the same symptoms at a later date.