A 2003 E46 325i wagon in Stahlblau Metallic. Rust on every panel. Zip-tied window regulators. I paid $2,600 for it and spent considerably more than I should have keeping it alive.

At some point I started looking for a keychain. Not a generic roundel thing. Not something from a gift shop. Something that meant this chassis. Something that said E46 to anyone who knew what that meant — and said nothing at all to anyone who didn’t.

I couldn’t find it. So I thought: I should make that.

At the time I had three BMWs — an E30, the E46, and an E70 — which is what put chassis codes in my head as a starting point. But the real problem was simpler than that: there was nowhere elegant to put your keys when you got home, and nothing worth looking at on your key ring.

What changed

Nothing dramatic. I just got tired of the idea living only in my head.

I’ve been a software developer for long enough to know that the distance between “I should build that” and actually building it is almost entirely psychological. The project doesn’t get harder when you start. It gets easier, because you finally have real problems to solve instead of imagined ones.

So I’m building it. This journey is the full record of doing that.

What I’m building

The core product started as a simple idea: a stainless steel keychain in the shape of the chassis code. The E30 letterform, cut from a single flat piece of stainless, with a key ring hole built into the E. No separate parts, no assembly. Just metal with negative space.

The hard part is the geometry. Each chassis code has to be designed as one connected piece. The letters bridged together so nothing falls apart when you pick it up. I’ve been working through that problem in Fusion 360 and I’m getting close to something I’m happy with.

The companion piece is a CNC-routered walnut wall mount. The keychain snaps in magnetically and sits flush with the wood face.

The part I like the most: they connect. Each holder is one car. They link together on the wall so as your garage changes, your wall changes with it. Buy a new car, add a holder. Sell one, remove it.. or better yet, give the keychain and holder to the new owner to add to their collection. There’s something right about that. The next owner gets a piece of the history.

The goal is something that looks intentional whether you have one car or four.

Why public

Because I have no idea if this will work, and I think that’s worth documenting.

Most product posts are retrospectives. “Here’s how I built a $10k/month business” — written after the fact, with the failures edited out and the timeline compressed.

I’m writing this as I go. That means some of these posts will be about things not working. The first prototype that snaps. The manufacturer that ghosts me. The first week with zero sales.

That’s the point. If you want to build something too, the useful information is in the failures.

Next: I’ll get into the actual design problem — why making E30 as a single stainless piece is harder than it looks.