There are two types of uninsured motorist coverages. One is for bodily injury and the other is for property damage. The other car owner would need to have the latter to claim the damages on their vehicles with uninsured motorist. If the drivers do not have this coverage they might have collision coverage which they could make their car damage claims under.

You didn't indicate your state, but as of August 2004, uninsured motorist property damage is available in these states: Alaska, Arkansas, California, Colorado, Delaware, District of Coulmbia, Georgia, Illinois, Indiana, Iowa, Louisiana, Maryland, Mississippi, New Jersey, New Mexico, North Carolina, Ohio, Oregon, Rhode Island, South Carolina, Texas, Tennessee, Utah, Virginia, Vermont, Washington, and West Virginia.

Even if the other vehicle owners have insurance to cover their damages they might decide to come after your uninsured son to reimburse them for their damages or deductible. If the drivers do not have coverages that will take care of their own property damage then most states would allow them to take your son, the at-fault party, to court to try and get a judgement against him that would pay them for their damages.