Well, that's the reason. Upon examination of the pics Wifey took on here cell, its failure to grease the slips. In the front, 90% of the slip is completely rusted off, and cracked all the way down to to the pinion flange. While the rear isn't as bad, it's close and causing driveline vibe.

Previous owner either a boob or a dipsheet.

Luckily, no pinion leaks. Shannon fortunately still has this under warranty sorta. When she got it as a result of a trade-in, she checked the Kia system and the last warranty claim was around 75k, but actual milage was SIGNIFICANTLY higher. She figures we can get 2-3 more years of warranty coverage, provided she continues to work at a Kia dealer.

As far as salt, as a result of lawsuits against NYState DOT for not doing enuff (due diligence) to keep roads from icing, they apply 100% pure rock salt, not salt/sand/gravel mix anymore. These rocks kick up from the tires, chip paint and coatings and start the rust. Rust blisters run rampant from there. As well, the salt dissolves and creates a "super-saline" solution that coats everything with a salt liquid many, many times more saline than the ocean, and can take days or even weeks to dry, all the while causing rust.

Many cars in NY have multiple locations of rust within 5 years, and cance riddled by 10.