David Evans, who has taken the role temporarily for a second time, said he was surprised when Mr Hines announced he was leaving.
He did not consult Mr Evans before handing in his notice and departing on the same day. “It was his decision and I was surprised, because Alan was head hunted and knew exactly what the job entailed,” he said.
“He simply decided he would resign and I don't know what went on in his mind. Things seemed to be working out alright. “There was no conflict over policy and, as far as I know, he did not have another job to go to.”
The RMI thought that, in Mr Hines, it had found a long-term successor to Christopher Macgowan, now SMMT chief executive. Mr Hines was previously managing director of Securicor's £175m turnover transport division.
In an interview this month with Automotive Management, Mr Hines said: “The RMI must be run effectively, so it is effective for members. Our members want a period of solid, sound and professional management. “Moving from a position in fleet management, I feel I am on the same battlefield but in a different trench – nothing has come as a great surprise.”