Bring a large pot of salted water to a boil, then add the ziti pasta. Cook according to package instructions until al dente, about 8-10 minutes. Drain and rinse under cold water.

Finely dice the red onion, red bell pepper, and celery. Combine in a large bowl, adding celery salt and celery seed, and stir in diced pimientos.

Grate and finely chop the carrot and add to the vegetables. In a separate bowl, whisk together sour cream and mayonnaise until smooth.

Sprinkle minced fresh parsley into the vegetable mixture and toss gently. Let it sit for about 15 minutes.

Pour the dressing over the vegetable mix and toss gently. Fold in the cooked ziti, ensuring every piece is coated.

Dice the cheddar cheese and fold it into the salad, ensuring even distribution.

Transfer to an airtight container and refrigerate for at least 4 to 6 hours or ideally overnight.

Before serving, give the salad a good stir and serve cold.