Driver Joshua Parkes and two 16-year-old female passengers died when the Skoda Fabia they were in crashed into a tree in Bromley Lane, Kingswinford, on Tuesday evening.
Passenger Nathan Cartwright died in hospital on Saturday and the fourth passenger in the car, another 16-year-old girl, is now in a stable condition in hospital.
Fundraising pages have been set up for each of the victims, with a combined total of more than £11,000 raised by Monday morning.
This includes more than £2,200 donated for the family of Nathan, who died four days after being taken to Queen Elizabeth Hospital in Birmingham.
Sophie Orourke, who created the page, said: "It is with great sadness to hear the news that Nathan sadly passed away.
"Nathan was in the car that crashed in Kingswinford after fighting for his life he sadly lost his fight and joined his friends.
"At such a sad time I would like to raise money to give to his family to help with the costs of the arrangements needed to be made.
"To help give him the send off he deserves.
"Every donation will be greatly appreciated and I'm sure his family will be very grateful.
"All donations will be passed onto Nathan's mom to help give him the greatest send off he deserves."
Invictus Education Trust chief executive officer Tony Bowles today paid tribute to Nathan, who was a former Crestwood School student.
He said: "On Saturday we received the devastating news that former Crestwood Student, Nathan Cartwright, 18, sadly passed away in hospital following the car accident on Bromley Lane that has been widely reported.
"The Crestwood School and Invictus Education Trust community have been left heartbroken by the news, we had all been hoping and praying Nathan could make a recovery.
"Nathan was a fantastic young man and a credit to his family, we have shared the picture of how we best remember him, surrounded by friends having helped his team mates to a league and cup double for the second year running.
"We pass on our deepest condolences to Nathan’s family, our thoughts are with you in these most difficult of times.
"It has been the most testing time in my 25 years working in education, and I know the pain is felt across the entire trust, particularly at Crestwood and Wombourne, where our staff have worked closely with these wonderful young people, building relationships and bonds that will never be forgotten."
Over the weekend Nathan's mother paid tribute to her son, saying: "My gorgeous boy Nath taken way too soon. You lived your short life to the full. You are at peace now."
The fundraiser for the family of Lucy Tibbetts, also a former Crestwood student, has raised more than £6,000 and more than £1,500 has been donated for the family of the other girl who died at the scene.
Her family have asked for her name not to be released and for their privacy to be respected.
And more than £1,000 has been raised for the family of 21-year-old driver Joshua Parkes.
His family have now released a tribute, written before Joshua's friend Nathan lost his life, which said: "The whole family are devastated at the loss of lives and pray that those in hospital make a full recovery.
"Our thoughts are with the other families involved at this dreadful time. We would appreciate our privacy being respected whilst we come to terms with what has happened."
Dozens of photos, flowers, cards and other tributes have since been left at the scene of the crash and hundreds of balloons were released in memory of the victims at Dell Stadium in Brierley Hill on Saturday.
Meanwhile the police investigation into the crash is continuing and anyone with information is asked to get in touch by calling 101 and quoting log 4469 of October 13.
To donate to Nathan's fundraiser go to gofundme.com/f/nathan-cartwright, to donate to Joshua's fundraiser go to www.gofundme.com/f/help-raise-money-to-help-the-family-of-josh-parkes and to donate to Lucy's fundraiser go to www.gofundme.com/f/rip-lucy-tibbetts.
We are not sharing the link to the fourth page to avoid publicising the victim's name.