In a skillet over medium heat, cook the bacon until crisp. Drain, cool, and crumble.
In a small bowl, whisk together the vinegar, mayonnaise, and sugar.
In a large bowl, mix the bacon, kidney beans, cabbage, celery, parsley, and onion. Season with salt and pepper. Pour the vinegar dressing mixture over the salad, and toss to coat. Refrigerate at least 1 hour before serving.