I put McLaren's new 'practical' $240,000 supercar to the test at Costco. It went way better than expected.

• The 2020 GT is the supposedly roomy McLaren, with extra space for luggage.
• It actually does have more cargo volume than the rear trunk of a Toyota Camry.
• To put it to the test, I took the GT to Costco and filled it up with stuff. The whole thing went shockingly well.

It almost sounds like a setup to a joke, this stunt that I pulled a few weeks ago. "A girl, her dad, and a McLaren all go to Costco…"

But if McLaren is going to come out swinging with its so-called GT — described by the automaker as its "first true McLaren Grand Tourer" and sporting an impressive 20.1 cubic feet of storage space to store your mid-engine supercar dreams and a whole bag of golf clubs — then I'm certainly going to put it to the test.

For those keeping count, the GT's 20.1 total cubic feet of storage space — which includes both the front and rear trunks — is actually greater than the 15.1 cubic feet of cargo volume you get in the single trunk of a Toyota Camry.

It's clear McLaren is trying something new with the GT. It's not utilitarian the way an SUV is, heavens no. But its structure has been modified — the engine height lowered and the exhaust system repositioned — to make extra room behind the passenger cabin for cargo.

As discussed in our review, the McLaren GT's rear trunk is very irregularly shaped. It's super long and flat, sloping over the engine, but not very tall. The deepest parts of it are right at the front and back, where the floor of that trunk lowers away from the ceiling of the car.

Being the thorough car reviewer that I am, I needed to test the usability of this vehicle. McLaren says the car has "room for luggage"? Well, then, that was an invitation to me to pack it to its fullest, a true test of cargo in bulk. I was taking the GT to Costco.

I was in luck, since my mom needed to go to Costco anyway to replenish some supplies at her office and pick up some food for my grandmother. My dad rode with me and she tagged along in her own car, just in case all the shopping didn't fit in the GT. Nobody expected it to.

I live in a Brooklyn apartment approximately the size of a shoebox, so I had forgotten that the rest of the US can actually bulk-buy things in such a fashion. Gallons of olive oil. Bags of rice starting at 25 pounds each. Blocks of cheese. TVs!

Shoppers skated about with carts the size of small sheds. My parents were busy filling theirs with facial tissues, oatmeal, chicken stock, and toilet paper. The more they loaded up, the happier I became.

In all, the purchases filled one Costco-sized shopping cart and included 12 boxes of facial tissue, 30 rolls of toilet paper, 200 trash bags, four containers of Quaker Oats oatmeal, three boxes of chicken stock, two three-pound bags of walnuts, three boxes of protein bars, a box of C-fold paper towels, a giant jug of white vinegar, a Kirkland-sized jar of garlic-stuffed olives, and a strawberry smoothie for me.

Before anything else happened, that strawberry smoothie went in the center cup holder. It fit perfectly.

The C-fold paper towels took up the most space, so we put those in the front trunk first. Then we stuffed smaller, loose items down around them, like the walnuts, the protein bars, and the olives. A small bag of groceries went on top of that.

The lid closed. Success!

The rear was a little more challenging because of the slope. Finally, though, we figured out a working arrangement.

The facial tissue, chicken stock, and vinegar went right up against the passenger cabin. Behind those went the toilet paper and the trash bags. We left the peak of the slope empty because the trunk wouldn't close with anything there. And down toward the tail of the car went more protein bars and the two boxes of oatmeal.

—kristen (@KristenLee) November 9, 2020

The lid closed, again. Success!

Look at that.

LOOK AT THAT, I SAY!

I am a genius.

We were shocked. The car swallowed up everything from the cart. Sure, it took a little while to figure out an arrangement that worked, but it all fit!

The biggest problem was rear visibility. Effectively, it dropped to zero. The wing mirrors can only do so much.

In retrospect, I'm not sure how much more we could have fit in the GT. Perhaps if we had softer items — like a big bag of rice or 47 pairs of sweatpants — they would have fit in the middle of the trunk. We'll put that on the list for next time.

But all of this made me curious. Can you fit a person in the GT's trunks? Here's the short answer.

Front trunk, no.

Rear trunk, yes. Surprisingly, yes!

With that big glass lid closed on top of me like a coffin, I felt like Snow White. Except I was far from dead.

I was elated, you see. Electrified with a new revelation: Not only is the McLaren GT highly practical, just as McLaren promised, but it's also a three-seater supercar. It is basically a McLaren F1.

Don't let the existence of merely two "seats" discourage you. With a little imagination, conviction, and a running jump — kidding, I didn't do a running jump — you, too, can become a set of golf clubs in the trunk of a $240,000 supercar. Just don't let your fellow passengers forget you back there.