2014-2020 BMW i8 Quarter Trim Panel: Replacing the i8's Signature Flying Buttress
A guide to inspecting, sourcing, and replacing the complex composite quarter trim panel on the 2014-2020 BMW i8 Coupe.
- This part is for the i8 Coupe ONLY and will not fit the Roadster model.
- Replacement is NOT a DIY job. It requires a BMW-certified collision center with training in carbon fiber (CFRP) repair due to the panel being bonded to the chassis.
- When buying a used panel, the most critical inspection points are hidden cracks and the integrity of all mounting tabs on the back.
- There are no reputable aftermarket options; a properly inspected used OEM panel is the only cost-effective alternative to a new dealer part.
Symptoms of a Damaged Quarter Trim Panel
Unlike mechanical parts, the failure of a quarter trim panel is always visible. There are no associated fault codes or drivability issues unless the panel is so damaged that it is at risk of detaching. Look for the following signs of damage:
- Cracks and Fractures: These are the most serious issues, typically resulting from an impact. Hairline cracks can grow over time and compromise the panel's integrity. Pay close attention to mounting points and edges.
- Scratches, Scuffs, and Rock Chips: Minor cosmetic damage is common due to the i8's low and wide stance. While often repairable, deep scratches may require significant bodywork before repainting.
- Punctures: A direct impact from sharp road debris or another object can puncture the thermoplastic material, requiring a full panel replacement.
- Broken Mounting Tabs: The panel is secured by a series of clips and bonding adhesive. If the mounting tabs on the backside are broken, the panel will not sit flush against the body, leading to poor fitment and potential rattling.
Known Issues, Recalls, and Service Bulletins
There are no recalls or common Technical Service Bulletins (TSBs) from BMW or the National Highway Traffic Safety Administration (NHTSA) related to a factory defect with the quarter trim panels themselves. All common failures are the result of external factors like collisions, impacts, or improper removal and installation.
Pro Tip: While there are no recalls for this specific panel, a service action (B513514) was issued for early 2014 models regarding underbody panels that could be damaged during transport, leading to vibration. This highlights the complexity and sensitivity of the i8's body components.
Buying a Used 2014-2020 i8 Quarter Trim Panel
Sourcing a good-quality used OEM panel is the most cost-effective way to repair a damaged i8, as reputable aftermarket versions are not available for this specialized part. Careful inspection is critical before you buy.
Warning: This part is for the BMW i8 Coupe model only. It will not fit the i8 Roadster (convertible) due to significant differences in the roofline, body structure, and rear quarter area.
Side-Specific Parts
Ensure you are ordering the correct panel for the side of the vehicle you need to repair. The part numbers are different for the left and right sides.
| Side | OEM Part Number |
|---|---|
| Right (Passenger Side) | 51627372044 |
| Left (Driver Side) | 51627372043 |
Critical Inspection Points for Used Panels
- Check for Hidden Cracks: Flex the panel slightly and inspect it under bright light to reveal any hairline cracks, especially around the mounting holes and edges.
- Look for Signs of Prior Repair: Feel the entire surface for waviness, sand marks, or areas that feel different. Improperly repaired composite panels can fail later. A professional body shop can often spot a bad repair that an untrained eye might miss.
- Inspect All Mounting Points: Carefully check the backside of the panel. Ensure all plastic tabs, clip receivers, and any bonded-on brackets are intact and free of stress marks or cracks. A panel with broken tabs will never align correctly. 🎬 Watch: Fitting a donor quarter panel on a salvage i8
- Assess Paint Condition: Assume you will need to repaint the part to match your vehicle. However, look for deep gouges or peeling that might indicate the need for extensive and costly prep work.
Replacement Information
Installation Difficulty: 5 out of 5 (Professional Recommended)
Replacing the quarter trim panel on a BMW i8 is not a DIY project. The vehicle's Carbon Fiber Reinforced Plastic (CFRP) chassis and bonded panel construction require specialized training, tools, and materials that only a BMW-certified collision repair facility will have.
The process is complex and involves:
- Removal of the rear wheel, fender liner, rear bumper, and taillight to access the panel's fasteners and bonded areas. 🎬 Watch: BMW i8 rear bumper and quarter panel removal
- Careful cutting of the factory bonding adhesive without damaging the underlying carbon fiber structure.
- Disconnecting any attached sensors, such as the keyless entry antenna.
- Meticulous preparation of the new panel and the vehicle's chassis.
- Application of a specific BMW-approved adhesive (like Betalink) and installation of new clips and fasteners to ensure a permanent, structurally sound bond.
Warning: An improper repair can compromise the vehicle's structural integrity, lead to panel gaps and alignment issues, and significantly reduce its value. Always use a body shop certified for BMW i-Series carbon fiber repair.
🎬 See how certified shops perform BMW carbon fiber repairsCost to Replace a BMW i8 Quarter Trim Panel
The cost is dominated by the highly specialized labor required for CFRP work. Rates for certified technicians can be much higher than for standard bodywork.
| Part/Service | Estimated Cost |
|---|---|
| New OEM Panel | $600 - $1,200 |
| Used OEM Panel | $175 - $500 |
| New Aftermarket Panel | Not Available |
| Shop Labor (Certified) | $2,000 - $4,500+ |
Note: Labor costs can vary significantly based on shop rates and the extent of any hidden damage found after the panel is removed. The total cost including the part, labor, and paint can easily exceed $5,000.
Frequently Asked Questions (FAQ)
What's the difference between a "Quarter Extension" and a "Quarter Trim Panel"?
They refer to the same part. "Quarter Trim Panel" or "Roof Moulding" are the official BMW terms. "Quarter Extension" is a more descriptive, colloquial term used by some sellers and mechanics.
Can I repair a cracked i8 quarter panel instead of replacing it?
Repairing the thermoplastic and underlying CFRP structure is highly specialized and often not recommended for anything beyond minor surface scuffs. For cracks or punctures, replacement is almost always the correct and safer procedure. An improper repair can fail and compromise the vehicle's structure.
Will a used panel match my car's paint color?
No. Even if the part comes from a car with the same color code, factors like sun exposure and batch variations mean it will not be a perfect match. Always plan on having a professional body shop paint and blend the used panel to match your car perfectly.
Is this a DIY-friendly repair?
Absolutely not. This repair requires specific knowledge of bonded composite panels, expensive specialized tools, and access to BMW's official repair procedures. Attempting this repair without proper training and equipment is very likely to cause further damage to the vehicle's expensive carbon fiber chassis.
Helpful Videos
Technical Specifications
OEM Part Numbers: 51627372044 (Right) 51627372043 (Left)
Material: Thermoplastic Composite. Attachment Method: Bonded with adhesive and secured with clips.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- BMW i8:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Symptoms of a Damaged Quarter Trim Panel
- Known Issues, Recalls, and Service Bulletins
- Buying a Used 2014-2020 i8 Quarter Trim Panel
- Side-Specific Parts
- Critical Inspection Points for Used Panels
- Replacement Information
- Installation Difficulty: 5 out of 5 (Professional Recommended)
- Cost to Replace a BMW i8 Quarter Trim Panel
- Frequently Asked Questions (FAQ)
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