There were two 1949 Buick Roadmasters used during the production of Rain Man, and Tom Cruise doesn’t own either of them. One of the Roadmasters used in the film was, until recently, part of his co-star Dustin Hoffman’s collection. Hoffman recently sold the Roadmaster to Bonham’s Scottsdale Auction where he fetched a price of $335,000 including buyer’s premium. Speaking before the sale, Hoffman said: “The Buick has been in storage for too long, it should be driven, enjoyed and cherished.” The other Buick Roadmaster featured in Rain Man belongs to the film’s director, Barry Levinson. Levinson described the car as having a “third billing” in the film, saying “it became a character. Dustin, Tom Cruise and the ’49 Buick.”
Although Cruise missed one of the two Roadmasters used in Rain Man himself, he may have the opportunity to borrow one, as QG states that he has used the car “off-camera on several trips across the country”. That said, Gentleman’s Quarterly also states that Cruise, “fell in love with the convertible and kept it,” and HotCars do the same. This contradicts what Bonham says about there being only two Buicks Rain Man, one going to Hoffman and the other to Levinson.
If Cruise occasionally cruises the Roadmaster, it’s also unlikely to be Hoffman, as the actor claims he stored it for decades before the sale. EngineBiscuit offers a more plausible explanation, simply stating that the actor liked the car and bought one independently after filming wrapped. Do with all of this what you want.