Coroner Richard McElrea has endorsed the work of the ''visiting drivers'' programme, being trialled in Queenstown by the New Zealand Transport Agency and partners.
The programme, which has a month to run, includes steering wheel tags with safety messages.
Mr McElrea called for a code of conduct for rental companies, if necessary by legal mandate.
It was also worth asking if passenger airbags could be made mandatory for all camper vans and other rental vehicles, he said.
And signs around the dashboard such as ''keep left'' should be compulsory for all rental vehicles, he said.
Mr McElrea, of Christchurch, made the comments in his findings on the death of Dunedin's David Morris, and German tourist Kerstin Fromert.
On December 28, 2011, Mr Morris (82) was killed on the Haast Highway, about 25km north of Haast.
The crash happened when German tourist Mathias Mandlmeier drove his Wicked Camper van on the wrong side of the road and it collided with the car in which Mr Morris was a passenger.
Ms Fromert (51) was a passenger in Mr Mandlmeier's car.
In his report, Mr McElrea endorsed the visiting drivers project, and recommended it involve the entire rental vehicle industry.
He recommended consideration be given for all rental vehicle operators to be bound by a code of conduct, either through membership of the Rental Vehicle Association or similar, and ''if necessary there be a legal mandate to enforce such a requirement''.
Wicked Campers management could not be contacted yesterday. The Rental Vehicle Association said the company was not a member.
Rental Vehicle Association chief executive Barry Kidd said his organisation did not agree with enforced membership.
''I think it's an interesting recommendation that requires further consideration. There's always issues around making anything compulsory.''
Encouragement was ''a better approach in the short term.''
The association had discussed the idea with the NZTA and other government agencies and there was ''a reluctance on their part'' to force operators to be part of industry organisations.
But Mr Kidd said operators who were part of industry organisations were keen to have opportunities to share best practice and to get an understanding of issues facing other operators.
''Operators who aren't part of those industry organisations don't have those opportunities.''
He said there would not be many rental vehicles in New Zealand without ''keep left'' stickers.
''We've supplied probably more in the last 12 months than we have for a long time. There's no excuse for anyone not having them.''
NZTA southern regional director Jim Harland said he agreed with the call for all rental companies to be signed to a code of practice, ''as do our partners in the process, and the New Zealand Tourist Industry Association is already working on that''.
He was confident safety initiatives would have a good take-up rate even without a law change, ''because there's really positive energy going into this from the industry''.
