Police said Mik Parslow, from Oxford, sustained multiple life-threatening injuries in the crash which happened on a bend of the A4095 in Oxfordshire.
Mr Parslow, who was driving a Toyota MR2, had to be cut free by firefighters before being taken to the John Radcliffe Hospital in Oxford.
On Facebook, his father Eric Parslow, thanked people for their messages of support after the "horrendous" crash.
He wrote: "He had multiple injuries from head-to-toe and the hospital spent many hours to stabilize him. Being kept sedated and on life support throughout.
"After four days with more surgery his scans revealed that his brain had been damaged to a point beyond recovery.
"Even had his broken body healed there was no hope for any sort of life. The decision was made to remove the life support and allow him to slip away peacefully."
Mik Parslow, who lived in Oxford, was described as "a great MR2 enthusiast" by the Malaysia Toyota MR2 Club.
In a Facebook post the group said: "[We] would like to pay our respects to Mik Parslow... who tragically passed away."
Dave Baileyâ€Ž wrote: "Such a shock, Mik only came over a few weeks ago in the car.
"I sorted another supercharger for it as his had a noisy bearing. Will be sadly missed by all who knew him. RIP."
The male Ford van driver sustained minor injuries in the crash near Radcot on 10 August but did not need hospital treatment.
A 45-year-old man has died in hospital seven days after a head-on collision.