Bethania Garage Inc. & Hard Dog Fabrication Hard Dog Fabrication Logo
The M4 Sport


Hard Dog is proud to introduce our Roll Bar for the 4th Generation MX-5 and Fiat 124 Spider. Built from heavy wall 1.75" diameter tubing these bars are a serious upgrades from the stock ND equipment. The aluminum factory cross brace and hoops are removed and replaced. A harness bar with an integral top latch bracket is included as standard equipment. The stock seat belts are retained without alteration.
The M4 Sport main hoop shares the same structural attachments as the factory hoop. Additional support is provided by 2 rearward braces w/ large 3/16" mounting and back-up reinforcement plates anchored with grade 8 bolts and self locking nuts.
Supplied with double diagonal main hoop braces or no diagonals.


  • Not sure which Roll Bar is right for you? Contact Us!

  • Protect your bean. Custom formed high density padding is now available for Hard Dog Roll Bars!

M4 Sport Features:

  • Meets NASA HPDE and SCCA Solo and Time Trials requirements when equipped with diagonal braces

  • Allows full seat travel and tilt

  • Complete use of soft top

  • Durable black powdercoat finish

  • Constructed from proprietary 1.75" diam x .120" wall, high strength, drawn over mandrel tubing

  • 2 rearward braces w/ 3/16" mounting and backup plates

  • Complete hardware kit w/ grade 8 bolts and self locking nuts

Roll Bar Accessories:

M4 Sport - 2016  and Newer Soft Top Models
- Contiguous 48 U.S. States Shipping $175.00
Item/Number Description
M4S Black Powdercoat
M4S2D Black Powdercoat w/ Double Diagonal
Stitched Covers w/ our Custom Formed High Density Padding - Cover Shipping $25.00 Contiguous U.S.
Item/Number Description
V Black Vinyl
L Black Leather
M4COV Rear Panel Covers (Pair)
Hard Dog Custom Formed High Density Padding - Pad Shipping $25.00 Contiguous U.S.
Item/Number Description
CPAD Formed Pad Only

M3 prototype - no diagonal
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M3 Sport
Double Diagonal w/ Panel Cover Installed.     

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M4S prototype install
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M4 Sport w/ Double Diagonals
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WARNING: This article is sold without warranty, expressed or implied. No warranty is made to this product's ability to protect the user from any injury or death. The user assumes that risk.

Updated Aug 15, 2021