Tesla Model Y Owners: How to Use the Sub-Trunk Space

Three ways to turn your Model Y's hidden lower storage into cold storage — from the engineer who built the first one.

Let me start with the thing I've earned the right to say: the world's first compressor fridge built for a Tesla sub-trunk was mine.

In 2023, my team launched TesFridge on Kickstarter — the first portable freezer engineered to drop into the Model Y, 3, and X sub-trunk. 1,703 backers. 7,271% funded. Shipped worldwide.

Being first meant I also heard every complaint first. And the biggest one came from my own driveway. That's the whole reason this article exists — and the reason I eventually went back and built a second, very different product.

Today, a Model Y owner who wants cold drinks on the road has three real options. I own and use all three. They don't solve the same problem. Here's the honest breakdown.

Option 1 — Fridge Y: the powered fridge (my original product)

Fridge Y drops into the rear sub-trunk and actually refrigerates and freezes. Bluetooth temperature control, roughly 30 minutes from 50°F down to -4°F. Meat, fruit, drinks — cold for days, no ice ever.

It's the most capable of the three. But the hidden cost is power.

The fridge itself only sips about 1% of battery per day. The problem is that to keep it running while parked, the car's "keep power on" mode has to stay active — and that burns roughly 4% per day. Call it ~5% per day combined. In summer sun, it's worse.

I learned this the hard way: I left for a business trip for one week, and came back to a Model Y down 40%. And if your 12V connection is loose, it can blow a fuse — or worse, trigger a low-voltage warning on the car.

Best for: owners who want true freezing and charge often enough that the drain doesn't matter.

⚠️ Fits the 5-seat Model Y only — the 7-seat sub-trunk runs about an inch tight.

Option 2 — Cooler Y: the power-free one I built to fix all that

After living with the drain on my own car, I went back to the bench and built the opposite kind of product. No plug. No 12V port. Zero battery drain.

Cooler Y is a 45 QT passive cooler, custom-molded for the same rear sub-trunk. PP shell, 2-inch PU insulation, 7-day ice retention (lab-tested at 90°F), dual compartments so drinks and food stay separate, and a sealed lid that won't leak in your trunk. Two full prototype rounds before I'd ship it.

The trade-off is honest: you add ice and deal with melt, and it doesn't freeze. But it costs you zero range, makes zero noise, and you just open and grab — no app, no electronics, nothing to fail.

The moment I knew it worked? Watching my kids and their friends crowd around it after basketball practice, everyone grabbing a cold drink, nobody complaining about warm water. That's the product test that actually matters.

Best for: most owners — anyone who wants cold drinks with absolutely no range loss.

⚠️ Also 5-seat Model Y only (2020–present).

Option 3 — Tesla's official frunk cooler

Tesla's own cooler is passive too, but it lives in the front trunk — a different location entirely. That's actually its best feature: it doesn't compete with the rear sub-trunk, so you can run it alongside either Fridge Y or Cooler Y.

It looks fantastic packed with ice and glass bottles. But living with it daily, two things wear on you.

First, it's a two-hand job. The frunk itself needs two hands to open, and so does the cooler's lid. If you're walking up with groceries or an armful of drinks, you can't do it one-handed — you end up setting everything on the ground first. Every single time.

Second, $275 is steep for a passive box, and it has production-date and trim fit limits, so check compatibility before buying.

Best for: owners who want to use the wasted frunk space and don't need active cooling.

Cooler Y vs. the Tesla cooler, side by side

I put both on my garage floor so you can see the difference that product-page photos never show.

Top (white) — Cooler Y. Notice the divider down the middle — drinks on one side, food on the other, so nothing gets soggy. There's a molded handle on each side you can grab one-handed, and the lid is hinged to the body, so it never goes anywhere.

Bottom (black) — Tesla's frunk cooler. One open bin, no compartments. And see how the lid is sitting separately below it? That's because it lifts completely off. Combined with a frunk that already needs two hands to open, that's the daily friction I keep coming back to: in practice you're using two hands and then hunting for somewhere to set the loose lid down.

Same idea — keep things cold without power. But one was designed around how you actually load it with your hands full, and one wasn't.

Side by side

My verdict: location first, then ask "do I want to plug it in?"

These three aren't rivals — they're complements.

If you want true cooling and freezing, and you charge often enough not to sweat the drain → Fridge Y.

If you want cold drinks with zero range loss and don't mind ice → Cooler Y. This is the sweet spot for most people, and it's exactly what Fridge Y's 40% drain taught me to build.

If you want to put the wasted frunk space to work → Tesla's frunk cooler, which stacks happily with either rear option.

From the first TesFridge to Cooler Y, I've been chasing the same thing: cold storage in a Model Y that actually lives up to the car. Cooler Y isn't a garage experiment — I built it for my own family first.

⚠️ One note for 7-seat owners: both Fridge Y and Cooler Y are molded for the 5-seat sub-trunk. The 7-seat version runs about an inch tight, so confirm your seat config before ordering.