Foreword & forewarning: This article is written for a Roadster/MX-5/Miata audience. Your experience may differ with a different car make and model. Please consult your local experienced locksmith for better details about which key types could possibly work with your car. Additionally, retrofitting any type of product not designed for your vehicle or application may result in issues unforseen in this article. Please proceed at your own risk.

Royal Clover. An aftermarket Japanese key brand with great notoriety for a key with the portrait of Queen Elisabeth II on it. There’s a lot of uncertainty surrounding the aftermarket automotive community about these keys that everybody goes crazy for. Why are these so popular? Why are they so difficult to find? Which keys fit my car?

During my time collecting keys for my Miata, I’ve come across these questions that nobody has real answers to and I had to search for some clues.

In this article, I will write about what I have discovered about these keys while collecting them for my Miata. Also, using my small key collection as a reference, I will show you which key codes are compatible with Miatas.

My girlfriend tells me to get rid of them.
A small collection of keys I’ve put together.

Welcome to the comprehensive guide to buying JDM “fashion keys”.


Market History

Miata keys have been known to be on the more fragile side for decades. When the key binds up while turning, this issue is most apparent. Most Miata keys have poor durability and had a tendency to fracture near the shoulder.

A common problem among Miata owners… Fractured keys.

Keys manufactured by the Japanese-based Royal Clover company were later discovered to have a bit more heft and Miata owners sought after them to help safeguard against this fracturing issue. With certain key models weighing in at 20 grams, it is easily almost double the weight of a standard key. They also feel fantastic in the hand.

However, Royal Clover did not intend on making these keys solely for the purpose of making them durable- they were actually created with the purpose of being fashionable accessories for the automotive market.

Unique finishes and fine details made fashion keys truly a work of art.

These fashion keys were originally meant to be a conversation piece. Set one of these beauties down at a party table and expect to have people around you chatter about it.

They were designed to be beautiful and ornate- and like most things that have a great amount of attention to detail, these keys were produced in a limited quantity. Now long discontinued, these fashion keys are becoming increasingly difficult to find uncut.

In the late 2000s, people were trading Royal Clover Duetto “Queen” keys at around $60 apiece, and by the mid 2010s, the market value was around $80 apiece. By summer 2018, they started to trade for about $300 apiece.

Thanks to social media, particularly Instagram and Facebook, their popularity grew exponentially. People sought after these “Queen” keys, modeled after the Australian 25-dollar 1/4 oz gold coin, as pieces of fine art rather than just a durable key.


Fitment and Cross-compatibility

While most Miata-specific keys (code M356) are difficult to find, the Miata’s lock tumblers are not restricted to just that code number. The main emphasis of the M356 is in the length between the shoulder and the head of the key.

With the Miata’s lock tumbler located far behind the stock wheel, Mazda used a key that required a longer shoulder-to-head length that made it easier to stick the key in and turn. However, it doesn’t mean it is the only key compatible with the Miata.

With the help of the local locksmith specialists, the following codes have been hypothesized to be compatible with the Miata, RX7, and other 90’s Mazda vehicles:

  • M166
  • M255
  • M327 (albeit it is on the short side with the head starting immediately at the shoulder)
  • M355
  • M356
  • M358
  • M360
  • M368

Of all of the codes listed above, code M360 was discovered to be thicker than the M356 keys. 

There are a few drawbacks to using a thicker key- it may not fit in an NB Miata tumbler. However, given that many NBs had anti-theft-chipped keys, fashion keys may not be applicable to most NB owners. Additionally, the M360 seems to fit only NA Miatas up to model year 1994- meaning you would need the older style lock tumbler to make it work.

The distance between the shoulder and head of the key differs between certain key codes, but an experienced locksmith should be able to correctly index and shave the shoulder to match the shank length you need. This is one trick to making the keys compatible for the Miata.

There may be additional modifications you need to perform to make these compatible for the Miata. As always recommended when modifying any product, proceed with caution at your own risk and do not use this article as a guaranteed methodology to cutting these keys. 

Brands and Key Styles

For details about fashion key make and models that I’ve collected, take a look at the Fashion Key Breakdown article I’ve written up.

You can also browse a catalog I’ve uploaded here:

Notable References

Key to My Heart