Trivia
Rachel's last name, "Amber" is possibly derived from the term "Amber Alert." The Amber Alert is an emergency response system that disseminates information about a missing person to the general public. This could refer to the "Missing" posters of Rachel Amber that are scattered throughout the town, or it could be a reference to Amber Hagerman (who, like Rachel Amber, was a girl who was kidnapped and eventually found dead).
Rachel's last name, "Amber", could also refer to the fossilized sap created by tree sap remaining underground for years. This could refer to her body being left in the junkyard for a long period of time.
It is foreshadowed that Max and Chloe will find Rachel in the junkyard; the Doe Max tries to photograph originally appears directly over the spot where she is buried. There is also part of a punk-rock shirt, similar to her style, torn and hanging near the spot.
In Chloe's room there is a postcard from Rachel saying she misses Chloe and wishes she were there with her. DONTNOD has confirmed that this postcard was in fact sent by Rachel herself.
The second time Max and Chloe go to the junkyard to confirm if Rachel's body is still there, Max can spot red (possibly blood) writing on the side of the den stating 'CHLOE WAS HERE, MAX WAS HERE, RACHEL WAS IS HERE' with Rachel's line now being in present tense rather than past. (Max's line is only visible if you chose to add on to the graffiti in episode 2.)
Rachel probably attended a Vortex Club Party on March 28, 2013, as a flyer Max can find in the junkyard's den hints to.
In Max's nightmare, Rachel's dormitory room number is 224. It is suggested that Rachel has lived in room 224 prior to her demise. The room has been taken over by Taylor Christensen after her disappearance.