The 2000+ Ford Taurus comes with hubcaps that bolt onto the wheels, and the snap on ones also fit on them.
The snap on ones hold into the outside edges of the wheel, and I think almost all steel wheels have the same type edges because of the way they are made. The lug nut hubcaps basically are just for style and because they usually stay on the wheel better, not because the snap on ones won't work.
Post a picture of your steel wheel, and a picture aiming at the inside edge of the steel wheel (like an angle with the camera near the lug nuts, facing the tire).
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