Turns out the car - a running prototype - was part of a sales event for current V8 owners, which we politely asked if we could gatecrash. It's not often you get an opportunity to poke around a £1.2m supercar, you see.
We already know that the 7.3-litre V12 is going to make the car 220mph fast, and that the One-77 will sound thoroughly glorious, but our gracious hosts allowed us to see how the car will feel from the driving seat.
"You can customise almost everything, too," one of the Aston peeps told me. "From interior trim and materials to throttle response. You have to stick to the standard power output," - and with an expected 720-750bhp who would want more - "but pretty much everything else is up for discussion."
Other highlights? The inboard dampers proudly displayed in the rear window are stunning-looking pieces of engineering, while the 3D-look badge on the car's rump is exquisite - more like a jewel than a car badge.
Customers for the One-77 will start to get their cars delivered before the end of the year and, on the basis of our all-too-brief encounter, they will be 77 very lucky people.