Bickering

My husband thinks our kids don’t like each other because they bicker and fight. How do we help them to get along using self-government? Examples: one child refuses to get in the car if she has to sit next to her brother and says really unkind things about why she won’t sit in the same row as him. Example two is one child tells another one to stop doing something and they won’t stop. Example 3: A child says a cutting comment about another sibling to a parent in front of them. We just want family unity! We have only been following your program for 7 or 8 weeks and it seems so hard to be consistent and learn how and when to give chores vs major maintenance or a SODAS when it is between the siblings. I have been carrying $5 in ones in my pocket to give them when they follow simple instructions with each other and so far o only have given out $1!