OK the googling of caliper cover shows after market jobs you slip over the original caliper cover. I hate to sound like a novice wrench turner, but if I could fix the issue without jacking up the car I would be thrilled. I never look forward to jacking my C4 up, especially this winter when there's a fuel tank and metal barriers about six inches from the nose of the car in my garage. This noise is worth chasing either way because it is too similar to the way the front end of the Saab Aero sounded when you turned the steering wheel.
I was told that the ball joints on the Saab were good. Come to find out later, the mechanic who diagnosed it didn't know enough to compress the springs first, then test for loose ball joints. After I brought that Saab back to the shop, they felt so badly, they put in a new rack n' pinion, brakes, rotors, etc. at no charge.
It's scary enough to have a car go out of control on you even if you have a chance of correcting your skid, but when you have a ball joint or two brake at 55mph, you're really on a magic carpet ride.
By the way, I've been told that Corvettes float at speeds above 110mph when you go to deaccelerate and that downshifting without braking, makes the car float, really like a magic carpet ride, LOL.
Happy Holidays to All