Detectives have identified a man whose body was found in the grounds of the Royal Alexandra Hospital in Paisley but his death remains unexplained.
Stephen Quigley, 26, was discovered off Craw Road at about 07:20 on Wednesday.
Police Scotland's major investigation team believe he may have been at an address in the area of Bourock Square, Barrhead, on Tuesday.
It is thought he then travelled from there at about 17:00 in a blue Ford Focus.
Officers want to speak to anyone in Barrhead or Paisley who have have seen the car on Tuesday evening to get in touch.
They are also keen to view any relevant dashcam footage that may have captured the vehicle being driven erratically or involved in any suspicious activity.
Separately, police said a 26-year-old man was seriously injured in an assault at the Barrhead address at about 02:00 on Wednesday.
Mr Quigley, from Neilston, East Renfrewshire, was identified after media appeal last week.
Det Ch Insp Scott McCallum said: "Stephen's family are being provided with support by specialist officers and have been updated. Our thoughts are with them at this time.
"We would urge anyone who believes they may have seen Stephen prior him being found on Wednesday morning to please get in touch as soon as possible."
Stephen is described as white, about 5ft 10in tall and of slim build with short dark hair.
At the time of his death, he was wearing a blue hooded top, black tracksuit bottoms and black trainers.