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R Theory NA/NB MX-5 Miata V1 Rear Diffuser Kit (1990-2005)

R Theory NA/NB MX-5 Miata V1 Rear Diffuser Kit (1990-2005)

All mounting hardware is included.

The R Theory Motorsports V1 Rear Diffuser Kit will make the rear of your Miata look amazing while giving it an aerodynamic edge.

It is constructed out of aluminum weighing only 9 LBS, but is strong and sturdy. All the parts are black powder coated for a durable and beautiful looking finish. Everything is 100% chassis mounted, no drilling or cutting is needed to make it fit. Gradient angle and length sticking out past the bumper is adjustable.

Only NB owners will need to cut out the pre-cut rectangle on the diffuser to clear the OEM tow hooks. It is recommended that NA owners remove one, or both OEM tow hooks for better fitment.


The difference between the 1990-1991 kits and the 1992-2005 kits is how the diffuser attaches to the rear subframe. The newer cars have a brace that goes across the rear section of the subframe that the diffuser attaches to. If you have a 1990-1991 car with a subframe from a newer car, you can go ahead of purchase the kit for the newer cars. You can see the brace in the install instructions below.

Exhaust fitment: As long as your aftermarket exhaust routes the same way as the OEM exhaust, the diffuser should clear it. Make sure that the muffler itself and the exhaust tip is roughly in the same location as OEM. The diffuser is designed to fit between a Miata dual exhaust muffler.

    Excluding GST/HST
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