I'm thinking about buying a Class IV hitch for my 2015 1500 Express. I installed the Class III hitch on my old 2010 1500 which just bolts to the last frame crossmember and was super easy to install. The Class IV bolts to the rear frame rails and looks pretty tight to the spare tire. How bad was the install? Did you have to drop the spare to get the hitch mounted? Please share your tips/experiences with the Class IV. Thanks.