that's the first time i've seen that note....... how strange. seems like she may have had some kind of epiphany & wanted to get away from it all... also it seems like her friends may have thought she was suicidal,, which is why she said she wasn't, she was 'the opposite'-- which suggests a state of euphoria... maybe brought on by the mental stress of being in her senior year (along with her parent's death & possible residual injury from the first car accident)... so it seems that people were worried about her. but what is odd, is that in the same note, she said some contradictory things... like 'here's money for the bills while i'm gone' and 'see you soon', which suggests she was coming back... but then, 'don't worry... time passes quickly.. have faith in me, you, everyone" and "give peter my laptop" makes it sound more like she is saying good-bye (and giving things away suggests suicide). 'see you soon' could have also meant, 'see you soon (after death)- because life passes quickly'.
it's all very vague and cryptic, and perhaps she didn't even know what she was searching for, or what she was going to do once she got to where she was going.
other things that are odd: driving cross country in THREE DAYS. that pretty much means she didn't sleep, and drove straight though without stopping for very long... which also strongly suggests a manic state. (unless..... someone was with her and helped with the driving...??? sometimes i think this is a reason why people run away mysteriously and suddenly, on their own accord-- they meet someone they have a strong connection with, and don't want to reveal it to anyone for fear of criticism, or.. 'they just wouldn't understand'. so, perhaps she met someone that no one else knew about?)
the fact that she went to see 'american beauty' suggests that she was not so much in a whacked-out or tormented state of mind that she couldn't see a popular movie... since they only found one ticket, she either went by herself, of if she was with someone- they could have paid & given her her ticket, or they both paid for their own.
either way, it certainly appears that she skidded off the road in the rain- or perhaps a lack of sleep & her mental state contributed to this.. & had a possible head injury.. maybe remained in the car all night due to the darkness & weather, and there was nowhere to go... covered the car with the blankets (to keep out the rain, or keep warm?)... maybe by the next day she was hungry, disoriented, desperate, lost, in pain or with a possible concussion.. all of which can impair your judgement.. and went up to the road for help & was picked up by someone with evil intentions.
the description says the car was wrecked, so i'm assuming that means undrivable- plus it was down an embankment, which means she probably wouldn't have been able to drive back up anyway. the windows being broken means one (or both) of 2 things: 1) if the accident was that bad, she probably bumped her head- but maybe not bad enough to bleed, since there was no blood found- or- 2), someone broke in after she left the car-- or while she was in the car. (but, they would've had to know she was down there.. if you couldn't see the car from the road).
it's also possible that she was speeding to get away from someone who was following her, when she wrecked.
OR.............. back to the beginning: maybe she really was suicidal-- and when she wrecked the car & was immobilized, it was more than she could take. telling friends 'i'm not suicidal, i'm the opposite' could still mean you are thinking about ending your life but view it as a type of freedom. or, perhaps she just didn't want her friends to worry. this possibility makes me think of the case of minna sandmeyer.. no one even considered suicide because she seemed happy, healthy, was socially active and well-loved. she also was a young (20-something) lady searching for meaning in life... and went off alone on a solitary bike trip.. everyone suspected she was abducted, so when they found her in the woods it was quite a shock.
http://thue.stanford.edu/jacquie/minna/
however, in leah's case, they already looked far & wide, and found no body...
strange they never found the kitten... did it just get loose & then perish in the woods? or they never found any food receipts... what/where was she eating? that could have offered some clues.. unless due to her mental state, she *wasn't* eating...
any other ideas?