Police said late yesterday afternoon Mr Windle's death was with the criminal investigation unit.
"A number of witnesses have been spoken to but inquiries are continuing,'' Detective Sergeant Dave Nelson, of the Dunedin CIB, said.
Det Sgt Nelson said the serious crash investigator was conducting inquiries and examinations of the vehicles involved.
Mr Windle's vehicle, two other custom cars and a late model sports car were travelling south to the Mid Winter Run on Friday when the crash occurred about 5.45pm.
Damaged vehicles were strewn across the highway after the crash.
Mr Windle's Ford was down a bank nearby.
Watch: Holiday weekend crash in Mangere
Emergency services personnel said at the scene it appeared a vehicle had crossed the centre line on a corner.
Mid Winter Run participants displayed their cars in the Octagon yesterday.
Friends said Mr Windle loved the 1937 Ford Cabriolet convertible in which he lost his life.
Danny Bisschop said Mr Windle had lived in Dunedin in the past, before moving to Kaikoura, and was about to move to Christchurch.
Mr Bisschop described him as "a great guy, so thoughtful''.
"We're just gutted, because he was coming down to spend some time with us.''
Mr Bisschop said the semi-retired businessman, like other hot rod owners, cared about his car, and drove carefully so as not to damage it.
Mr Bisschop said Mr Windle would have wanted the Mid Winter Run to go ahead.
Hurricane Rodders president Wayne Nicol said the club considered stopping the event, but it was agreed it would take place.
There had been "a bit of a toast'' for Mr Windle at the event, and the club next year would consider changing its name to a memorial event for him.
