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1990-05 Hard Dog Sport roll bar (double diagonal)

1990-05 Hard Dog Sport roll bar (double diagonal)
1990-05 Hard Dog Sport roll bar (double diagonal)
Our favorite street bar.

Made in the USA

This item will be dropshipped from the manufacturer.


Originally known as the "M2", this is our favorite street bar for the 1990-05 cars. It works with all factory tops - hard and soft, glass or plastic window. It doesn't affect seat travel. The bar is well placed to stay clear of your head while still providing protection. Made of 1.5" DOM tubing.

The biggest downside to this bar is that it's not as tall as the Hard Core. The top of the bar is 19" above the rear parcel shelf. This may be an issue when dealing with your local track day organizers, so we recommend checking the necessary clearance required. Most of them will know this bar by name.

The design has recently been tweaked to accept a wider variety of top designs - it will now clear a glass window that is up to an inch larger than the stock NB window.

If you'd like to use a harness, harness tabs for eyebolts are an available option at the time of order for an additional cost but this option must be ordered directly from Hard Dog Fabrication. You can also use the bolt-in harness bar (available separately, here:

Shipping note: These bars will be drop-shipped from the manufacturer. These bars are usually kept in stock. If not, depending on where the bars are in the production process, it could take approximately 2-6 weeks for delivery. If you would like one shipped outside the US, please contact Hard Dog Fabrication directly.

Additional Information

Additional Information

Part number 20-18000 2 DIAG
Fits: 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1999, 2000, 2001, 2002, 2003, 2004 (non-MSM), 2005 (non-MSM), MSM
Manufacturer Hard Dog
Flyin' Miata exclusive No
Fits Exocet? No
Proposition 65 Warning: Cancer and reproductive harm
California emissions Emissions regulations do not apply

Customer Reviews 9 item(s)

Solid, Baby
This bar looks good, stiffens up the ride, and I've waited 3 long years to write this review to tell you that it was the best purchase I've made for this car. Being that the Miata is a unibody- it is inherently wobbly and will flex on you when you put your car through hard turns. With a proper roll bar like this, you are tying in the top half of this car together to be firm and prevent all that body warp you'd normally subject the car to.

Did I mention this bar looks cool with the top down?
Review by Reisce / (Posted on 4/30/2020)
Worth every penny
I was concerned about buying the Hard Dog Sport Double Diagonal because of my height (I'm 6'2"). I'm happy to say that I have no issues with hitting my head, however I do plan to add padding in case I get hit from behind. I have no problems with the view from the rear-view mirror. The install took 8 hours (as all of the U-tube videos said it would), and I did the full install solo. Love the way it looks in my '01 (Emerald Green with tan interior). I've owned several Mazdas ('75 rotary pick-up, '87 B2000, '92 B2600, '93 B3000, '07 3i Touring), but this is my first MX-5.
Review by Tom / (Posted on 5/18/2019)
Great Roll Bar and Highly Recommended
I am 6 ft 200 lbs and the bar fits perfect for me. I followed two different Youtube videos while installing this with a friend and learned to make sure to have all the proper tools while doing this for the best fitment.

Miata University:


Follow these to videos and you will be fine. I watched them three times each before installing to know for sure what to expect going in. Overall, great quality roll bar and highly suggested to buy.
Review by Reese / (Posted on 5/7/2019)
Not for tall people
It was a sad day for my much-loved Miata when this bar was installed. Visibility and seating position have never been the same. The bar is low and forward enough that my head hits it. Forward goes the seat and up goes the seatback. Welcome to your new car with cramped seating and crummy sightlines. Even the safety improvement is mixed. If I ever get rear-ended, my head is hitting that bar hard.
Maybe these problems are non-issues if you aren't so tall (I'm 6'1"). Maybe the M1 bar would have given more space.
That said, fit, finish and quality of build are all good. That two-star rating is a compromise. Product quality earns a 4-5 star review. What it did to my car earns 1 star.
I wish someone had warned me. If I had to do this over, I'd have ordered an M1 with a single diagonal (so I could see out the RV mirror) or the Deuce.

Note from FM: We're sorry to hear it didn't work out. Tall people and roll bars are a problem for Miatas. The problem is that they have to fit under the top. The taller the bar, the further forward it has to sit. Push it back, the bar gets shorter. The Deuce sits further back but is considerably shorter than the Sport. The M1 bar gives the exact same clearance as this one does.
The single diagonal bars have worse rear view for some people and better for others. We've found that, on average, the double diagonals are acceptable for a greater proportion of the population.
Review by Pete EE / (Posted on 8/13/2018)
Great bar, the name - not so much
Almost didn't buy this bar because of the name. I know that's a stupid reason but "hard dog" reminds me of some drunk frat boy trying to high five everyone at a hooters. Then I figured if Flyin Miata offers it it must be good so I ordered one. I wasn't disappointed. Fit and finish were excellent. I have to admit I was surprised how well it lined up with the factory mounts. It took me almost a full day to mount as I'm a bit anal and I also made a new rear carpet since I'm running a hard top and pulled the soft top assembly out. Also opted for the padding which I would recommend as tall folks may bump their head when things get fun. I know some people have complained about the instructions - they aren't included (you have to look them up online) but they aren't that bad. Maybe save the 4:20 for when you're done? All in all I'm very pleased and happy to have the added safety and chassis stiffening.
Review by Swifty - because my buddy says I'm not too / (Posted on 5/14/2017)
Great bar, great price, worth it
Great bar, install took a full day, you'll need two people to place it in the car because lots of things need to be moved around as it goes in and you just need four hands. Other than that I did the install completely alone, it's not fun but it can be done. Looks great and fit nice and snug on my 2003. Rear visibility is very significantly reduced but not to a dangerous level, still very easy to live with and a small price to pay for safety. Definitely worth it, would recommend.
Review by Jett B / (Posted on 1/23/2017)
Unreal Customer Support from Hard Dog
This Company is a joy to work with.

I had heard about Bethania Garage/Hard Dog Fabrication and the roll bar products they make for the Mazda Miata from many friends who have similar vehicles. I was told the products were popular and great quality.

The real quality at Bethania Garage/Hard Dog Fabrication is their unbelievable customer service. Before my purchase, Tom answered all of my fitment questions honestly, fully, and quickly. He mentioned his own personal experience, and didn't even steer me towards the most expensive bars, but ones he thought would fit my needs. I ended up deciding to buy an M2 Sport Bar with Double Diagonals.

Fast forward a week and a half: I pull up to my house today to find my package waiting (so excited!) and pick it up only to find the box and packaging have been DESTROYED by FedEx. The box was holed in several places, the protective wrap on the bar was torn through, and the powder coating on the bar was missing in several places. Not a great feeling when you are so pumped to get your new parts... So I sent an email to Martha (she had sent me the tracking info), detailing my predicament. We discussed how I felt we should proceed to correct the issue, and she said she would look into it. While I waited, I typed up an email to send to Bethania, just restating everything I had said on the phone so I had a record of it. Ten minutes after I hit send, Martha called me back and said that her and Tom had a chance to talk, and that they would be happy to correct the issue in either of the ways I had suggested. I made my choice, Martha cheerily thanked me (I was the only one who should have been saying that!), and I am now a happy customer who would suggest Bethania/Hard Dog to anyone and everyone!

Buy here, you won't regret it!
Review by Jay V. / (Posted on 7/1/2016)
Great Roll Bar
Fairly straight forward install. Didn't come with paper instructions but honestly they are not really necessary with YouTube and the online instructions. Pretty straight forward install, works great fitting under the soft top on my '94, feels very solid, and looks awesome.
Review by amatthews4851 / (Posted on 9/23/2015)
Good bars, terrible instructions.
The bars themselves appear to be of excellent construction. HOWEVER, the instructions that are included are terrible. I have a 2003 Shinsen and got the Hard Dog Sport (Double Diagonal). The instructions were primarily for installing some sort of micky mouse double loop thing. This meant that there were instructions to do several things that I didn’t have to do, and several very important instructions that were totally omitted. I’ve installed other brands in Miatas with few problems. The instructions included probably caused me to waste over 3 hours.
If you are going to lay out over $450, insist on a proper set of instructions. If they are too cheap to produce the right ones, there are other excellent bars on the market.

(note from Flyin' Miata: the instructions can be found at for anyone who would like to preview them. We suspect the wrong ones were accidentally provided in this case)
Review by Shinsen sensei / (Posted on 5/27/2015)
Instructions for this part are not currently available online.