My husband and I have co-signed for our son's car loan, and also he is listed on our car insurance coverage. If he gets in an accident, can we be sued?
Yes you can be sued successfully. Also if he loans his car to a friend, and that friend does something negligent you can be sued successfully for that as well.
In the view of personal liability, you as a cosigner, are just as good as an owner.
In my own case, my child owns her own car and has her own insurance. We are not on the title of the car and there is no loan on the car. However, she does live with us. Given all that, we are likely to be sued if she or someone driving her car does something negligent. As such we carry high liability coverage on our home owners and automotive policies. She also carries that same high liability coverage.
If your net worth is over 300K, it is likely that an umbrella policy might be in order.