The victim's BMW X6 was broken into in Glasgow's West End.
It was parked in Kirklee Terrace, near Great Western Road. Luxury watches and computer equipment were among the thieves' haul.
Police have appealed to anyone with information to come forward, and now the victim is offering a £1000 reward for information which helps catch the thieves.
The break-in occurred overnight on Monday, October 15. Two Panerai watches worth £8000 each, a MacBook worth £1800 and a £1500 set of Callaway golf clubs were stolen.
An £800 cashmere jacket, two pairs of Ray Ban sunglasses worth £150 each and a £300 Dunhill pen were also taken in the raid.
Personal documents and credit cards were stolen.
The victim, who wants to remain anonymous, said: "I am really sickened by the incident. There are items which have sentimental value which were stolen, not to mention personal documents, credit cards and my passport.
"There is obviously the hassle of having to have my passport and other documents replaced, but there are other items which I would like to be reunited with."
The 52-year-old man added: "I am willing to offer a £1000 reward in the hope that my belongings could be returned to me and those responsible caught.
"I hope someone is able to come forward with information about the theft from my car or someone who knows where the items may have ended up."
Anyone with information is urged to contact Maryhill CID on 0141 531 3700.