Alex Ryder was living her dream in Byron Bay.

"In love ... with life! Never been so excited about the future!" the 29-year-old teacher and waitress posted on Facebook when she moved there in 2013.

The woman with the "infectious personality" moved to the North Coast after wishing for a life in the picturesque region where she could live off the land, surf and embrace the outdoors.

After almost two years, her rich life ended abruptly on Wednesday.

She was standing up through the sunroof of a car when it crashed into a tree on Skinners Shoot Road on Tuesday night.

A passer-by rushed to help and carried out CPR until paramedics arrived.

She was flown to Gold Coast University Hospital where she died on Wednesday, surrounded by family.

It is understood a 22-year-old friend was driving the car in Byron Bay's back streets when it crashed.

It is unclear how fast the car was travelling, but a source said no tyre marks were on the road.

Police say the driver, who was not injured, was taken to hospital to undergo mandatory blood and urine tests.

The Harvest Cafe, the restaurant in the Byron Bay hinterland where Ms Ryder worked, closed on Thursday as colleagues mourned her death.

Ms Ryder had also worked casually as a teacher in the area.

Her sister, Adriana Ryder, was one of many friends and relatives who paid tribute on social media.

"My love for you is undying," she posted on Facebook.

Jaydey McCarthy wrote of Ms Ryder's infectious personality and the lives she touched.

"May her spirit live on forever in our hearts," she posted.

Police investigations continue..