{"product_id":"mmx-90mm-billet-coolant-cap-bmw","title":"MMR Performance Aluminium 90mm Coolant Expansion\/Header Tank Cap for BMW and MINI with OE 17 11 7 639 021 \/ 17117639021","description":"\u003cdiv\u003e\n  \u003cp\u003e\n    Elevate your engine bay with this premium alloy radiator header tank lid from MMR Performance. Precision‑machined in the UK from a single piece of aluminium for a robust, high‑quality finish, this 90 mm reservoir top is a direct‑fit replacement for the factory unit on selected BMW and MINI applications using the correct OE reference.\n  \u003c\/p\u003e\n\n  \u003cp\u003e\n    Unlike flimsy stick‑on covers, this is a complete replacement reservoir cap that installs in place of the standard item for an authentic, OEM‑style fit and a cleaner performance look.\n  \u003c\/p\u003e\n\n  \u003cp\u003e\n    Verified compatibility: vehicles fitted with OE reference 17 11 7 639 021 (also written 17117639021). Please cross‑check your existing tank lid before ordering.\n  \u003c\/p\u003e\n\n  \u003cul\u003e\n    \u003cli\u003eSolid aluminium construction for long‑term confidence and a premium feel\u003c\/li\u003e\n    \u003cli\u003eDirect fit on cars using OE 17 11 7 639 021 — no adapters, no covers\u003c\/li\u003e\n    \u003cli\u003e90 mm diameter design for the correct seating on the expansion system\u003c\/li\u003e\n    \u003cli\u003eUK‑designed quality from MMR Performance with a tidy, motorsport‑inspired finish\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003cp\u003e\n    We run this part on our own builds and it’s been a favourite with our customers for its superb fit, reassuring quality and slick engine‑bay upgrade. If you’re searching for a radiator reservoir cap, expansion tank lid, engine coolant bottle top, water tank cover, alloy header tank cap, performance reservoir lid or 90 mm coolant tank cap for BMW\/MINI models using the above OE reference, this is the solution.\n  \u003c\/p\u003e\n\n  \u003cp\u003e\n    Part number (OE reference): 17 11 7 639 021 \/ 17117639021\n  \u003c\/p\u003e\n\n  \u003cp\u003e\n    Need it installed? Book professional fitting with MJ Modifications in Warwickshire. Request a quote: \u003ca href=\"mailto:info@mjmodifications.co.uk\"\u003einfo@mjmodifications.co.uk\u003c\/a\u003e.\n  \u003c\/p\u003e\n\u003c\/div\u003e","brand":"Champion Rainbow Co. Ltd (Previously Golden Bloom)","offers":[{"title":"Default Title","offer_id":56496630235522,"sku":"MMR03-1502","price":101.49,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0871\/5445\/8937\/files\/MMR03-1502_2.png?v=1774093736","url":"https:\/\/mjmodifications.co.uk\/products\/mmx-90mm-billet-coolant-cap-bmw","provider":"MJ Modifications","version":"1.0","type":"link"}