That promoted three separate complaints to the Advertising Standards Authority, saying it misrepresented the policy.
In particular, the complainants argued the Porsche would have been over the $80,000 limit for the subsidy in the Government's policy, while the 1990s Toyota Corolla would have been too old to import. The levies only apply to cars being newly imported under the policy.
"These facts were clearly not checked prior to publication and despite many respondents on Twitter pointing out that the claims were false the tweet has not been altered nor removed," one complainant wrote.
But in its reply, National said the Toyota could have been made in 1999 and still imported in 2021 and that the Ministry of Transport has specifically listed the Porsche as an eligible vehicle.
The ASA concluded while National had used extreme examples of what the policy could do, it was clearly labelled as representing the Opposition view, and that National had given enough evidence to substantiate its claim.
It also noted the importance of freedom in political advertising.
The decision comes as political parties decide whether to sign up for a new Facebook tool aimed at creating transparency around online political ads.
The Facebook Ad Library is a database that lets the public see how much money is being spent on political ads and who they are targeted at – but it's not compulsory in New Zealand as in some other countries.
Only the Green Party has so far agreed to sign up.
Prime Minister Jacinda Ardern on Monday said the project was "to be applauded".
She did not go as far as saying Labour would commit, but hinted it might.
"We haven't made any formal announcements ... but it's something, as I say, it's encouraging," Ardern said.
"It's a positive move on their part and we'll have something to say on it soon."
The National Party has previously said it would consider the initiative.
