What is the ruling on working in the spare parts trade and dealing with insurance companies, and paying a commission to employees to sell 70% of the goods that are exclusively sold to them, with a desire to cease this dealing but needing time to do so?

If you cannot sell these items except by paying commissions to employees, then it is permissible for you to do so, because bribery is permissible for the one who offers it if it is the only way to obtain one's right, while it remains forbidden for the one who receives it. However, you must search for another permissible means, for necessity is determined by its extent.