That model would set New Zealand's newest multi-millionaire back about $150,000.
Kevin said the Dodge Viper had not been ordered - at least, not yet.
"He has been looking at second-hand ones - you don't buy that sort of thing new," Kevin said.
Trevor, who has been lying low since he went public with his win and does not want his full name revealed, had always liked Vipers - even before his big win, said Kevin.
"He drives a Chev Blazer as his day-to-day drive and he has a Silverado [pickup] he has been restoring over the years."
Trevor treated mum Shirley to a new set of wheels from a third dealership after her car blew up on the way home from collecting the Lotto win in Wellington.
But Kevin said his son hadn't made any other big purchases and his family were keeping him grounded.
"There is no house yet. He is not used to having money to spend so he hasn't been going around spending a lot. He has his mum and sister to answer to," Kevin joked.
The 34-year-old's first two weeks as a millionaire were spent camping with his extended family on a pre-arranged holiday up north and fixing cars.
Kevin said his son wanted to stay out of the spotlight after being overwhelmed by the attention since his win.
He said many people were looking for scandal but confirmed his son was single and had no children of his own.
"Someone said he had a stepdaughter but that was actually the daughter of his flatmate and no, they are not in a relationship," Kevin said.
Meanwhile, it's not quite $26.7 million - but a lucky Christchurch punter won $5.5m in last night's PowerBall draw. And Auckland siblings Scott and Kim spun $250,000 on the Winning Wheel.