One major factor is figuring out the quality of the repair. Who fixed it? Was it a "factory" body shop with ties to the automaker? Or was it a cheap repair job done as quickly as possible? Your mechanic should be able to tell you his opinion. But if paint colors don't match or panels don't properly fit, that's a sign it wasn't a thorough fix -- and there could be more issues underneath. We also recommend looking at emblems and badges. A car that was hit in back and lost its emblems may be a sign that the body shop cut corners on the repair.
Similarly, left turn accidents are almost always the fault of the driver taking the left turn. Cars coming straight into an intersection will have the right of way in most cases, making the car turning left responsible for the accident. If the car going straight through the intersection is speeding or runs a red light, this may shift some or all of the liability away from the car turning left. Rarely, if the car started turning left while it was safe to do so, but was forced to stop because of some unforeseen circumstance, then some of the liability may be shifted.