The SUM Endorsement also contains underinsured coverage which applies when the vehicle which causes the accident has a liability insurance policy limit which is smaller than the underinsured motorist policy limit for the car in which you are the driver or passenger. For example, when a Hyundai disregards a stop sign and crashes into the side of Mercedes, if the Hyundai has a liability policy limit of $25,000.00 per person and the Mercedes has an underinsured motorist policy limit of $100,000.00 per person, an occupant of the Mercedes may settle with the Hyundai's insurance company for $25,000.00 and then seek $75,000.00 from the underinsured motorist endorsement of the Mercedes policy.