Contact the radio station that plays Rush in your area. Just do a google search and email them using their “contact us” link. Ask them to pass on to the advertisers that dumped Rush that you will no longer use any of their products. If they won’t stand by Rush, then they won’t stand by their product.
After you do that, contact other national radio hosts and ask them to drop these companies as sponsors. If these companies don't want conservative dollars, conservative talk shows shouldn't promote them.