BMW M3 M4 4 Series 2021+ CSL Yellow Headlight DRL Module Upgrade

This BayOptiks headlight component is designed around the listed vehicle applications and selected configuration. Confirm the complete fitment, factory equipment, finish, quantity, and installation requirements before ordering.

Key Features

• Complete CSL Yellow DRL LED boards for left and right headlights.
• OEM Switchback turn signal functionality retained.

Fitment

Specifications

What’s Included

One new BayOptiks product in the exact quantity and configuration identified by the product title and selected option. Mounting hardware, adapters, modules, wiring, seals, emblems, cameras, sensors, and companion trim are included only when expressly stated for that configuration.

About BayOptiks

BayOptiks offers application-specific automotive lighting and exterior styling products. Compatibility depends on the exact vehicle, factory equipment, production split, and selected configuration.

Related BayOptiks Products

• BMW M4 4 Series Coupe 2021-Present CSL Yellow Headlight DRL Module Upgrade
• BMW 7 Series 2019-2021 CSL Yellow Headlight DRL Module Upgrade
• BMW M3 M4 2018-20 CSL Yellow Headlight DRL Module Upgrade

Browse the BayOptiks collection for related lighting and exterior styling components.

Frequently Asked Questions

Will this fit my 2021-2025 BMW 420d?
That application is listed, but confirm the complete product title, body style, trim, factory bumper or lighting package, production split, selected configuration, and every product note before ordering.

Do I need to match my factory headlight or tail-light type?
Yes. Adaptive, non-adaptive, laser, LED, xenon, halogen, market specification, and connector differences can change compatibility. Select the exact configuration installed on the vehicle.

Will coding or wiring changes be required?
Requirements vary by product and vehicle. Review the current BayOptiks instructions for modules, adapters, coding, aiming, sealing, and warning-light behavior before installation.

Are these sold as a pair or as one side?
Use the exact title and selected option to confirm quantity and side. Do not assume a pair is included when the listing identifies driver or passenger side only.

Installation Instructions

Follow the current BayOptiks instructions and vehicle service information for this exact configuration. Verify the vehicle, factory equipment, selected option, tools, hardware, wiring, sealing, aiming, clearances, surface preparation, cure times, and final operation. Test-fit before permanent modification and use a qualified installer when coding, wiring, body adjustment, drilling, bonding, or lighting aim is required.