You should call around to a few machine shops.I have a 300 SDL and know first hand that they do corrode on the inner lip that contacts the wheel and a assortment of different years and models can have this happen. If your lucky you might contact a shop with an Ultra-sonic bolt releasing tool , works like a jiffy every time!! It mounts to the wheel and uses sound waves to slowly deteriorate the corrosion around the lug threads, allowing you to remove the broken studs with a simple pair of pliers.