Sounds like the car was abused. I would stay away from it and look for something that is sold in stock shape -or- buy a new model that someone hasn't abused.
Just my two cents:
The '15s and newer have independent
suspension. They will jump around a little more in a straight line race, but it will corner better than the '14 and older cars.
'12, '13, and '14
Pros: More room under the hood
Solid rear axle (good for drag racing)
Frame and door build quality seems better than newer models (more solid)
All used, so more affordable
Cons: Solid rear axle (rear end will slide out during cornering; can be fixed with a Watts link stabilizer for $900)
All used/more miles on motors at this point
'15-'16:
Pros: Can be new or used with low miles
Independent rear
suspension (rear end will not slide out during cornering)
Can be bought in 4 cylinder turbo (if you want to upgrade the turbo immediately....)
Supposedly tuned to a higher HP (430 horse in the V8 opposed to 415 horse in previous model)
Come with line lock (if you are not the best at brake torquing a standard shift car
Cons: Newer, so they are more expensive
Independent rear
suspension (wheel hop during drag racing)
Frame and door build quality seems lesser than previous model (seems flimsy in comparison)
Less room under the hood
As an engineer, I prefer the older model because it can be upgraded easily. But then you have to wonder what was done to it previously.