I have to agree with your analysis. You're in a bad spot. This is why we buy insurance. Learn a lesson and go out and protect that Mercedes. It';s crazy to own a car worth anything and not have insurance protecting yourself from all the crazies and irresponsible people out there - a good lesson to learn now. Sorry for your trouble.
Every situation is different, and good legal advice cannot be given based on a short question without an exploration of all the facts that may bear on your situation. This is not legal advice and no attorney-client relationship has been established.
Sorry to say your time might be better spent doing things other than pursuing this guy. Theoretically you could file a case in small claims court and get a judgment, if you can find him and serve him. Once you get the judgment, if he doesn't pay you could spend alot of time having his wages garnished, but he would probably just find another job that you don't know about.
Filing a small claims lawsuit is simple. You fill out the form and pay a filing fee. You will then need to pay to have a Sheriff or other process server personally serve the guy with your Complaint. If he works under the table and has been evasive to you, it's possible he might be difficult to serve. The court sets a hearing date that will not be too far out. You will have to provide documentation confirming that the guy was served with your Complaint.
At the hearing, you will need to bring a copy of the traffic collision report, photographs of the damage to your vehicle and all documents concerning cost of repairs, and any amounts for loss of use or a rental car. It sounds like a judgment would be entered in your favor.
So at that point, you will have a judgement against the guy. Of course, a judgment is really just a piece of paper unless you have a way to collect from the guy. You would then need to bring a creditor action against him. You would have to file such an action and then obtain as much info as you can about where he works, who he works for, his bank account and credit card info, etc. It sounds doubtful that he owns any property, so there won't be anything else to attach the judgment to. The judgment will be in force for 10 years and can be renewed. Of course, the guy could file for bankruptcy and that will completely discharge his debt to you.
Unfortunately, you will need to put a lot of time and effort into pursuing him....and you will likely not collect a dime from him.
Sorry to say small claims seems to be your only option. Even if you get a judgment you will unlikely be able to collect. I know, its extremely irritating when people do not take responsibility for their actions.
If you have insurance go through the insurance and let them handle the recovery against the UM driver. Other wise you will need to proceed to small claims and try to collect. You can try contacting the investigating officer and see if they will forward to the DA for prosecution. If so the Court can order the defendant reimburse all expenses.
You can file in Small Claims and have the Sheriff attempt service at all three of the addresses he provided. However, it's possible that none of them are accurate. Giving three services addresses also probably increases your service fees by 300%.
Further, your judgment will be useless. How will you levy his wages when he doesn't have a "real job"? Clearly, he has no assets.
You would be better off spending your time and money repairing your vehicle and, in the future, buy comprehensive/collision insurance and/or UIM coverage.