I have just recently begun to look into this case and have to admit I am in no means an expert on any of the details, but in the little bits of information I have heard on various podcasts and read about in various locations I feel confident of my opinions below:
1. Maura did not vanish to begin a new life or runaway from the men in her life. I am not the expert on this case that James Renner is, but I just have not seen evidence to support this theory, and after all this time I feel strongly she would have been discovered by now.
2. In my opinion the family, in particular Maura's father and sister have been on the receiving end of some baseless claims and attacks. Does that mean I think they know more than has been reported? I am not sure at this point, but don't feel that they are involved.
Which leaves me with three remaining scenarios that are possible:
1. Maura was abducted by a stranger, which seems at least possible, but the likelihood in such a remote area seems far fetched, but again not impossible
2. Maura succumbed to the elements after either evading the accident site or do to injury sustained in the accident, but I think after the searches done some sort of evidence would have been located.
And number 3 and my own opinion and speculation, which in my mind has way to may coincidences to not be possible and according to Occam's principle has merit. Maura was heading to NH for some reason and people have speculated on the reason for a long time, which is supposition at best. A person has stated that they were familiar with the area of the crash and were in the area in or around the same time as Maura went missing, possibly even driving past the crash. This person, in the very least, was familiar with Maura and her group of friends at UMASS including Maura's best friend and now has some sort of relationship with Maura's then boyfriend. This person has interjected themselves into the case and have attempted to steer the facts and direction of the case. We don't know much, or even if there was a gathering or party the night Maura crashed her father's car at UMASS, but from people's word at least Maura and two friends were in a dorm room drinking prior to that crash, this person described was acquainted with at least one of the people at this "gathering", so my own speculation is this person could have possibly been in that dorm room. Of the UMASS names mentioned as friends that I have seen, it appears Maura's friend base were fellow members of the track and cross country team, which this person was as well. We have seen phone records that the boyfriend contacted Maura's best friend on one occasion, so the boyfriend was at least familiar with Maura's group of friends to some degree. I believe it is a possibility that Maura created a story to excuse her from classes and intended to meet up with at least this one person, but possibly others in NH and was heading to this location when the crash occurred and may have been driving in tandem with others to get to this location, which was a mere hour from the crash site. How or if Maura made it to the location is unknown and I am in way insinuating anything sinister was perpetrated by this person or Maura's boyfriend. Heck, this person may have assisted Maura is her disappearing if that were the case, which I don't feel it is the case. I don't know what happened after that crash, but I have seen that the theories of local residences continue to be proved futile, as no trace evidence at any of their properties has been located. Certainly there were some sketchy people in that area, but after the amount of investigation conducted something would have tied these folks to Maura. There is evidence to show that Maura was driving a direction familiar to this one person and towards a location that this person could quite possibly have been at that time which is may be mere coincidence, but odds would have to be very low for that to happen. I have not seen any sort of proof of this person being in the location, other than their word, but would be curious to see whom they were in the area with, their activities during their time in the area, and what they were driving at the time.
Clearly I will not name this person, but they can be found online and the information I have used to come to my opinion can also be found online.
Again just the opinions of a casual observer from about as far away from the location as is possible in this country.