"Although arrests have been made we would still like to hear from anyone with any information about this matter, especially members of the public who were present in the Otaki Beach area when the vehicle was abandoned," Detective Sergeant Peter Vine says.
"Your information is still valuable to us."
Anyone with information is urged to contact Levin CIB on (06) 366 0500, or Crimestoppers anonymously on 0800 555 111.