A man suffered severe head injuries when the four-wheel drive car he was travelling in flipped over and crushed him, an inquest heard.
Paul Dunn’s body was half thrown out of the open sunroof when the 4x4 somersaulted through the air in the early hours of September 16 last year.
The 35-year-old labourer, of Saturn Way, Hemel Hempstead, is believed to have been at the wheel.
He was on his way home from a pub when the accident happened at a roundabout in Long Lane close to the M25 eastbound slip road in Rickmansworth.
An inquest into his death on Wednesday heard that there was some doubt over whether Mr Dunn or his friend Martin Kavanagh – a witness at the Hatfield hearing – was driving at the time.
But after hearing evidence from Mr Kavanagh and police experts, Herts coroner Edward Thomas said: “I think it was more likely than not that Paul was driving.”
The pair, who were both around three times over the drink-drive limit and had been smoking cannabis, were not wearing seat belts at the time of the accident.
PC Robert Jackson, from the Herts police road collision investigation unit, said: “It would be like being in a tumble dryer.”
It is believed the vehicle was travelling at around 45mph when it approached the roundabout – too fast to get around it, according to PC Jackson.
Father-of-six Mr Kavanagh, who also had cocaine in his system, suffered a severe ankle sprain, scrapes and bruises.
He had purchased the 4x4 for around £600 several weeks earlier and sold it to Mr Dunn a couple of days before the accident in a handshake deal with the expectation that money would be paid later.
Inspection of the vehicle revealed that it had tinted windows that were below the legal limit, a slightly under-inflated tyre, and the suspension system had suffered wear, which made it ‘significantly less stable, particularly when cornering.’ There was also a problem with the ABS braking system.
Mr Thomas ruled that Mr Dunn died from a traumatic head injury as a result of a road traffic collision.
He said: “He would have died instantaneously, there is no question about that. He wouldn’t have known anything about it.”