Rear muffler kit, “OPF-Back” – For M135i rear bumper model – Full kit only – Kit 04484

Product & Manufacturing Details

• Manufactured in Italy – Supersprint has been designing and manufacturing premium performance exhaust systems since 1955 and is recognised worldwide for exceptional engineering, vehicle-specific fitment, and proven performance development.
• Premium Stainless Steel Construction – Supersprint exhaust systems are manufactured using high-quality stainless steel and premium materials for excellent durability, corrosion resistance, and long service life.
• Vehicle-Specific Design – Every Supersprint exhaust system is engineered and tested for the specific vehicle application to optimise exhaust flow, performance, sound quality, and fitment.
• Extensive Research & Development – Supersprint designs are validated through extensive road, dyno, and performance testing to ensure consistent quality and reliable results.
• Factory Order & Lead Times – Many Supersprint products are sourced directly from Italy. Where items are not available from UK stock, typical lead times are approximately 7–14 working days, although some specialist applications may require longer. We will keep you informed throughout the ordering process and provide delivery updates where applicable.

Warranty & Quality Assurance

• 36-Month Manufacturer's Warranty – Supersprint products are covered by a manufacturer's warranty for a period of 36 months from the date of delivery.
• Warranty Coverage – The warranty applies to defects in materials and workmanship and is valid for the original purchaser only.
• Warranty Exclusions – The warranty does not cover damage caused by vehicle accidents, modifications, misuse, competition or motorsport use, incorrect installation, or external influences.
• Labour Costs – The manufacturer's warranty does not cover labour charges, removal costs, refitting costs, shipping costs, or ancillary parts required during replacement.
• Defects Process – Any suspected manufacturing defect will be assessed by Supersprint's technical department, who will determine whether repair, replacement, or another remedy is appropriate under the warranty terms.

Returns & Refunds

• Items ordered or shipped incorrectly by us will be refunded or replaced with the correct parts.
• Special-order and factory-order products sourced specifically for a customer may not be eligible for cancellation or return unless faulty or supplied incorrectly.
• Stock items ordered in error by the customer may be accepted for return at our discretion and are subject to return shipping costs and a re-stocking charge (currently 15%).
• Damaged deliveries must be signed for as damaged or refused and reported to us immediately upon receipt.
• Products found to have a manufacturing defect will be handled in accordance with Supersprint's warranty procedures.

Mail-Order & Specially Ordered Items

• Special-order Supersprint products must be paid for in full before ordering from the manufacturer.
• Mail-order exhaust systems, components, and accessories must be paid for in full before despatch.
• Delivery times are estimates and may vary depending on manufacturer availability and international transport schedules.

Onsite Works & Project Vehicles: Fitment and Installation

• Customers may retain original vehicle parts removed during installation. This must be agreed and documented on the Workshop Job Card before work commences.
• Retained parts must be collected within 7 business days unless alternative arrangements have been agreed. Uncollected parts may be disposed of without further notice.
• We recommend that all Supersprint exhaust systems are installed by suitably qualified technicians. Incorrect installation may affect performance and may invalidate the manufacturer's warranty.