The front-seat passenger, Michael Crusan, 36, of Flat Rock, was in critical condition this morning at Spectrum Butterworth Hospital in Grand Rapids.
The driver, Robert Cain, 37, of Grand Rapids, was treated for his injuries and released, a hospital spokesperson said.
Cain was driving a 2005 Nissan Z westbound on a curvy section of Luce Road, about 10:38 p.m. Sunday. He lost control and the car turned 180 degrees before the back of the car struck a tree, Buter said.
The crash is still under investigation.