Mercedes (2005+) Cylinder Head Expansion Plug (x1) rear freeze r171 w203 w204 Expansion Plug On Cylinder Head Rear 30 mm Brand NEW part with full 1 year warranty. Mercedes part# 000 998 65 90, check fit below. Genuine Mercedes part, recently made: not been lying around. Please see FITMENT CHART below, under PRODUCT DESCRIPTION. Email us your VIN for any questions.