If I sue the insured, who pays if the amount is in excess of the coverage?

With that kind of money you need to speak to an attorney. You would like a recovery from the wrongdoer(s) and its/his/her/their insurer(s) pay(s) to the extent of the policy/policies and you'd then try to collect the balance from the wrongdoer(s).

The insurance company's exposure is $100,000; that?s why it's called policy limit. If damages exceed that limit, the other driver is exposed. If you intend to seek all the damages as mentioned in your question, be careful about signing a release. Unless the o.d. is wealthy and steps up to do the right thing, you will probably have to file suit and take it to judgment. Then you will face the problem of collecting, as the o.d. will have had a couple of years in which to hide his/her assets or file bankruptcy.

Your suit would be against the car owner and the driver, not the insurance carrier because they are not liable for the accident [they merely have a contract obligation with their insured]. Do you have any additional insurance that might cover the damages? The insurance carrier would pay the first $100,000 of any judgment you might get and then you would have to go against the driver and car owner for the rest. Do they have any assets that you can reach? ?Collecting a judgment can be a time consuming and non-productive. Was the driver acting in the course of any employment or using a company vehicle so that you can allege negligent entrustment against the employer? The insurance carrier has an obligation to the insured to try to settle the matter within policy limits but not above that [I do not think the insured can argue the insurance agent did not warn him to consider higher limits because $100,000 is extremely high which suggests it was a company vehicle, a very expense vehicle, or the owner has a lot of money so enforcing a judgment should not be too difficult]. In order to avoid the costs of trial and providing an attorney to the insured, the insurance company might try to interplead the $100,000 limits [turn the money over to the court to hand out once you get a judgment]. Once you file suit, you will want to send out discovery, especially Requests for Admissions, to establish liability and that the amount of your damages is not contested so that you can move for summary judgment. If you decide to hire an attorney, you probably would want to hire them on an hourly basis and not percentage of the recovery over the $100,000 already offered unless it is a low percentage or the likelihood of recovering anything from the driver and/or owner is very low [judgments are good for ten years and can be renewed indefinitely]. Good luck.