You are quite right, check this article which says that Russia has refused the entry of used cars due to this and the dealers in Japan are selling the effected cars, but in Pakistan people have more faith in JDM stickers than anything and will never accept it :
Radioactive cars being sold in Japan
This is what is written in the article:
Car dealers who often export used vehicles to Russia and Southeast Asia are having shipments to those countries refused because of high radiation levels. Customs authorities in Russia have turned away hundreds of vehicles that were shipped to their country by Japanese used car dealers. Russia has been joined by Chile and Australia, who have both received shipments of automobiles contaminated with low levels of radiation". I am sure all these cars will be shipped to Pakistan as no one will check them here and people will buy them with their eyes closed as they are the " holy JDM cars".
A used car dealer in the Fukushima prefecture said, βIf they have Fukushima or Iwaki number plates, we re-register the cars elsewhere in the Kanto region and then auction them." To stop this unscrupulous business practice the managing director of the Japan Automobile Exporters Association, Yutaka Shioda, said, βAll cars being auctioned in Japan should undergo radioactivity tests.β
Radiation-Tainted Japanese Car Parts Confiscated At Russia's Far Eastern Border
Also see that other countries are testing the Japanese cars but we will not as " Japanese are angels, they can't do anything wrong "
Australian vehicles imported from Japan to be radiation tested | Car Advice
And this news is allso worth checking "Radioactive Used Cars Being Sold Illegally in Japan"
Radioactive Used Cars Being Sold Illegally in Japan | Fox News