Detective Sergeant Dave Wilkinson said they were particularly interested in speaking with people near the Brynderwyn Summit and Artillery Rd, between 7pm and 10pm on Friday.
Police also appealed for any dashcam footage the public may have that could be of use for their investigation into the Tauranga man's death.
Clark's family plans to celebrate his life at a service on Monday at the Otumoetai Golf Club in the Bay of Plenty - the place, they say, he first fell in love with the sport.
Anyone with information is encouraged to contact police on 105 and quote event number P051784129.