One of the fundamentals of insurance is that you have to have an insurable interest. Your friends wheels do not fall under this category. As to the wheels your wheels did not incur any damage and as such will not be replaced or paid out. If you were underinsured ie got the benefit of paying a lesser premium, you will be paid out a percentage. I am not sure as to the wording of your insurance contract and say the above from the perspective of general rules of insurance.
It is normally not in your best interest to go the legal route for the difference.
Just my 2 cents worth.
