I’d get the carfax report and see what is discovered. It will tell you if the car was a rental, lease, or owned title. It will tell you where the car was sold originally and where it was registered, and if it was an auction car. It may indicate some service work, but service is sometimes captured by carfax and sometimes not. There is another service similar to carfax so you can shop for a best price for this kind of info.
Anthing is possible, the car could have been purchased and the owner passed away and the car may have sat for some time while an estate settled. Or, it could have been damaged and sat waiting for parts for a repair. It could have been a retired couple that used the car infrequently. It could have been in a flood and was repaired and shipped to an “non flood” area for resale. You just don’t know.
If the factory warranty is still valid, I’d go ahead and buy the car. If there is no factory warranty, that means there is something in the history that voids the warranty and then I’d leave it and look around some more. I think most factory warranties are transferrable and Subaru is 3 years and at least 30K miles so the warranty should be available, if indeed it is a good car.
A dealer warranty is not a factory mfger’s warranty. Neither is an “aftermarket extended warranty”. I am talking about the same warranty Subaru would offer on a new car. Get clarification of the warranty that comes with car and the carfax report and if you are still concerned, then pass on it.
My guess is for a few more dollars you can get a new car in this market, and perhaps that is the best way to ease your mind. All used cars are for sale for a reason. Sometimes you can determine the reason and the car is fine, other times you discover the reason after you own it and then you own the problem as well.