It’s surprising how quickly an insurance company will ‘total’ a car. The insurance company merely compares the cost of repairs to the remaining value of the car at the time of the incident in making their decision. Repairs are so costly, that many times they are quick to ‘total’ the vehicle. Since the car was hit from behind, you shouldn’t have any engine problems. This is encouraging since unanticipated engine problems could result in you being stuck with ongoing engine repairs that never end. If the current owner merely replaced fenders and bumpers, you shouldn’t have a problem; however, I would be very concerned with undisclosed damage to the frame. A car with a damaged frame can result in the car never holding an alignment, and you wearing out tires every couple of months. In addition, you ought to check with your current insurance agent to make sure you won’t have any issues in insuring the car. Lastly, a major consideration is one you already entertained. You will need to drive the car until it dies, since resale of a ‘salvage titled’ car will be very difficult.