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Exterior Components› Body Panels and Components

R Theory Motorsports

V1 Rear Diffuser Kit

Name: V1 Rear Diffuser Kit
Brand: R Theory Motorsports
SKU: 998-107-001

$375.91

SKU: 998-107-001

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$100 Minimum Order

Non-Returnable Item

DIY PRO SHOP

Moderate — 2–4 hours

Overview

The R Theory V1 Rear Diffuser Kit is designed to enhance the aerodynamics and aesthetics of your Mazda MX-5 NA and NB. This lightweight diffuser, weighing only 4kg, is constructed from all-aluminium with a durable black powder-coated finish. It is 100% chassis mounted, requiring no drilling or cutting for installation. The gradient angle and length are adjustable.

Show original supplier description

The R Theory V1 Rear Diffuser Kit is engineered to give your Mazda MX-5 NA (Mk1) and NB (Mk2) a striking appearance while providing an aerodynamic advantage. The finish is a durable and attractive black powder coating. Installation is designed to be straightforward with its 100% chassis-mounted system, eliminating the need for drilling or cutting into your vehicle. The diffuser's angle and how far it extends past the bumper are adjustable, allowing for a customized look. For NB owners, a pre-cut rectangle on the diffuser must be cut out to accommodate the OEM tow hooks. NA owners are advised to remove one or both of the OEM tow hooks for optimal fitment. Owners of 1989-early 1992 chassis models should note that these early cars lacked the under braces found on later models. An extra set of brackets will be required for installation on these specific years.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

Brand	R Theory Motorsports
Part Number	998-107-001
Category	Exterior Components

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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