I had some of that develop really quickly with the cheap coolant.
G-05 is my suggestion for a premium coolant.
Instant protection unlike dexcool. That's right, Dexcool doesn't do anything for a while. Have to let it "steep" or "ferment".
Great news: Ford and Chrysler are now using Dexcool as well.
OP: Check out the condition of the struts, control arm bushings, rear trailing arms if they're the U channel design. Consider new tires, at the very least, an alignment.
Also consider all new fluids all around: Brakes, coolant, power steering, engine oil, transmission.