I would lay odds on this being Robert Heinlein's The Door into Summer, first published in 1956.
The novel opens in 1970 with Daniel Boone Davis, an engineer and inventor, well into a long drinking binge. He has lost his company, Hired Girl, Inc., to his partner Miles Gentry and the company bookkeeper, Belle Darkin. She had been Dan's fiancée, deceiving him into giving her enough voting stock to allow her and Miles to seize control. Dan's only friend in the world is his cat, "Pete", a feisty tomcat who hates going outdoors in the snow.
Hired Girl, Inc. manufactures robot vacuum cleaners, but Dan had been developing a new line of all-purpose household robots, Flexible Frank, when Miles announces his intention to sell the company (and Flexible Frank) to Mannix Enterprises in which Miles would become a vice-president. Wishing to stay independent, Dan opposes the takeover, but is outvoted and then fired as Chief Engineer. Left with a large financial settlement, and his remaining Hired Girl stock, he elects to take "cold sleep" (suspended animation), hoping to wake up thirty years later to a brighter future. The examining doctor at the cold sleep facility immediately sees that Dan has been drinking. He warns him to show up sober or not at all 24 hours later for the actual procedure.
After becoming sober, Dan decides instead to mount a counter-attack. First he mails his Hired Girl stock certificate to the one person he trusts, Miles' stepdaughter Frederica "Ricky" Virginia Gentry. Dan confronts Miles and finds Belle in Miles' home. Belle injects him with an illegal "zombie" drug, reducing him to somnolent compliance. Belle and Miles discover Dan's plans to go into cold sleep and have him committed.
Dan wakes up in the year 2000 with no money to his name and no idea how to find the people he once knew. What little money Belle let him keep went with the collapse of Mannix in 1987. He has lost Pete the cat, who fled Miles' house after Dan was drugged, and has no idea how to find a now middle-aged Ricky.
What does not match is that the cat does not get cryogenically preserved (although the company Dan originally contracted with arranged for him to be put under as well), and his car does not go missing until after he's drugged, a problem for his conspirators rather than him, because he left plans and documents in the car.
The twist is that the car was indeed, stolen, but by him, after he discovers a way to travel back into the past.
Incidentally, you probably finished the first third of the book, based on the details you provided.