As I mentioned. Not everyone has suspension problems. The plant in Mexico could have gotten a supply of bad wheel bearings or bushings or a lack of supervision upon the installation of them. Only a guess at this point. I do know that there are thousands upon thousands of PT that don't have any problem with these parts, including mine (
knock on wood) with 94,000 miles on the odometer.
Don't go looking for problems that aren't there but do have the undercarriage, and front suspension checked out at the next service. It's called Preventive Maintenance.