I have several projects on the to-do list for my 2004 Mazda RX-8, but I had been procrastinating because I hated dealing with its plastic fasteners. These are designed to fit in holes roughly 8mm in diameter and hold two or more pieces together. Usually at least one of those pieces is a flexible body trim panel.

They are made from two pieces: an center portion that pushes against the outer portion so the latter expands to hold the fastener in place.

Here’s what the head looks like in the fastened state.

In theory, we release this fastener by a quarter-turn of a Philips-head screwdriver.

This pushes a few wedges/ramps against each other and pops the center free, allowing the outer portion to contract and letting us pull the fastener out of its hole.

In practice, years of road dirt and grime jams up the works so the center doesn’t want to turn. Applying more torque risks stripping the slot, and the typical technique to avoid cam-out is to push my screwdriver harder inward. This force directly defeats the purpose of the turn, which is to pop the center outward! I’ve always felt it was a bad design to put such forces in direct opposition to each other. Despite my efforts to avoid damage I would end up stripping the inner slot and have to find some other way to release the fastener. This usually ends up damaging the fastener (this one’s outer ring is cracked) as well as the panels it had fastened to.

I’m not sure if these are factory original Mazda parts, but I do know I have came across multiple different fasteners on my car. Some of them might have been fitted by mechanics who have worked on my car over the past two decades. I understand why they would perform such substitution, and I will follow their lead.

My criteria was to find something advertised for 8mm holes and suited for outdoor environment applications. These are pretty generic commodity parts used across multiple industries for different purposes, but there doesn’t seem to be a commonly agreed upon name for these things. I settled on an Amazon product that just incorporated a bunch of different into its lengthy title: 200PCS 8mm UTV ATV Fender Push Clips with Fastener Removal Tool, Nylon Body Rivets Fasteners Clips Compatible with Polaris Ranger RZR Can Am Kawasaki Teryx Honda Suzuki Sportsman (*)

And the best part: this design doesn’t require self-defeating forces to remove. Again this center component is designed to pop out, but this time it’s not the turn of a Philips screwdriver. Instead, this has side slots for me to pry against to pop them out.

On the downside, these lowest-bidder items are definitely not as nicely made, with crude plastic injection molding flash all over. Diameter of the head is not as large as my original fasteners, and length is slightly longer. Despite these differences they seem sufficient due to the loose tolerance nature of the application. They are good enough for today but the real test will come years down the line when I try to release one seized up from years of dirt and grime. I figured even if it doesn’t release, I could take a large pair of diagonal cutters and cut it off. I know how to get plenty of replacements.

Having that option is great, because it greatly eased projects that require dealing with such plastic fasteners. And I already have one on my hands: tracking down a coolant leak.

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(*) Disclosure: As an Amazon Associate I earn from qualifying purchases