Persistent fuel odor in vehicle cabin every time gas tank was filled. Tank was NOT overfilled. Problem was identified when car was taken in to Mercedes-certified mechanic (not dealer) for inspection. Problem presented fire hazard (and cancer hazard due to breathing fumes). Car could not be driven until problem was resolved. Mechanic discovered cracks in the collar of the fuel pump mechanism in rear of car. Required removing and replacing entire assembly. Discussed problem with Mercedes dealer, but no reimbursement was offered. This problem has been repeatedly reported in E-Series Mercedes vehicles with recall issued, but no recall was issued for C-Series vehicles. The E-Series recall involved a manufacturing defect in the fuel system part. This is a problem about which Mercedes is well-aware, and repairs should be covered by dealer.