wheel studs
The W210 as well as most other MB's use lug bolts rather than studs and lug nuts. Once the wheel is off try some WD40 or penetrating oil to loose the broken end of the lug bolt and unscrew it. It's best to re-torque lug bolts about every 6 months to prevent seizure especially in northern climates.
The original bolts extend out past the mushroom portion but are vulnerable to seizing and snapping. The new replacement bolts are shorter and do not stick out flush to the rim.
This will probably cause some on this site to yell at me, but I believe in using anti-seize occasionally on the threads of lugs. This keeps the threads from rusting and galling.




