A detailed R170 SLK32 owner catalogs the AMG-specific wear items: the supercharger clutch-pulley bearing (dealer replaces the whole clutch/pulley unit ~$1000, though the bearing alone is ~$60-70 and a DIY with an oven and freezer), a hard-to-source AMG-only secondary air injection pump needed to pass California smog, fragile heated-seat wiring, trunk struts, and a roof scissor pin that lost its circlip and stuck the top.
SLK32 AMG ownership costs: supercharger bearing, air pump, roof pins
Mercedes-Benz SLK / SLC · ownership