Police have new leads on the four-year-old cold case of missing Waikato man Rick Hayward after asking the public for help on Police 10-7 last week.
Frederick "Rick" Hayward, 67, was last seen leaving his home around 5pm on September 2 2013, with the intention of travelling to the family bach in Raglan.
His red car was found empty at the summit of Old Mountain Rd, halfway to Raglan.
Police now believe something "sinister" happened to the married father of two - with one theory being that he was the victim of a hit-and-run, and someone disposed of his body.
Hamilton police are now appealing for sightings of two vehicles around the time he was reported missing.
One is a dark-coloured Nissan Terrano, similar to the one pictured, on Old Mountain Rd, near the Karamu track.
Investigators are also keen to hear from anyone who saw another ute, possibly with TX in the number plate.
"We are interested in talking to people who may have knowledge of these vehicles, particularly if they have sustained any damage," Detective Sergeant Andrew Saunders said.
"We understand we are asking people to think back almost four years, but there will be regular users of Old Mountain Rd who might recall seeing the vehicles we have described. This would include people spotlighting in the area."
Anyone with information can call 0800 HAYWARD (0800 4299 273) or Crimestoppers anonymously on 0800 555 111.