When you are billing the claims out to the Auto Accident insurance, update the insurance information in the Demographics > Auto Accident section.
This will give you the option to enter all of the applicable information and have that information populate in the appropriate place on the claim form.
After entering the information under Auto Accident, ensure that the payment profile under the appointment is listing Auto Accident for any claims that need to go to the auto payer. The system will know, based on the payment profile you select, to bill to the payer listed under Auto Accident, instead of Primary Ins. When you are ready to bill the claim, select the status Auto Accident Claim under claim status in the Live Claims Feed.