Such a hard question to answer really, but the simple answer is yes, a used rally car can be safe. Every rally car to this point that I've owned has been used. If you're not mechanically incline find a friend that is, if you don't have any friends that are, talk to people in the rally community and see if someone could help you take a look at a car with you. There's always things to look at on rally cars because of the harsh environment they live in. The biggest thing is knowing what you're getting into and if you can take care of things yourself.