Class Action Suits

I have received several letters in the mail about class action law suits pertaining to my '13 TDI. I am not in a hurry to jump on the bandwagon but my question is: Do any of you have info on what happens if I do not respond to these? If there is a successful suit does an owner have to be registered with that law firm, or any firm to get an award or are all owners (regardless if they join a specific law firm or not) eligible for an award?

Nothing happens if you don't respond. If there is a class action lawsuit, you will automatically be part of the class if you own / owned an affected vehicle as of a certain date (likely the date at which the Notice of Violation was filed and became public, or somewhere near that, last September).
It is virtually guaranteed that the alternative dispute resolution being set up by Feinberg will put you much, much further ahead than participating in any of the independent lawsuits. Again, you don't need to do anything for the moment.
This thread will be locked but left public because this question has already been asked several times.