Update December 31, 2016: You've got the rest of the day to pick up Codemasters' classic racer, GRID, before it vanishes.
Previously GRID was being given away for free on Humble, and it's seemingly because some licenses were about to expire, causing the game to no longer be available for sale. The racer has already vanished from Steam, and it's due to disappear from GOG later tonight.
If racing games are your thing, we have a list of the best at that link.
Luckily, GOG have GRID on sale for $3 right now, and once you own it you can download at your leisure - it just won't appear for new buyers. The racer is scheduled to be removed from GOG at 6pm ET, December 31.
I've emailed the PR agency who deal with Codemasters and asked if they can elaborate on the license expiry and will update if they get back to me.
Original Story December 22, 2016: If you like driving games, you might have played Codemasters' GRID when it released almost a decade ago. It's considered a classic among racing fans, and you can grab it for free if you're quick.
"Discover a stunning world of motor sport brought to life, from racing muscle cars through the iconic streets of San Francisco and competing in the legendary 24 hours of Le Mans to drifting around the docks of Yokohama," says the official blurb. "Jump behind the wheel of exhilarating racing cars in the most aggressive, spectacular wheel-to-wheel races you've ever experienced."
Take part in muscle car races, drifts and circuits through a variety of urban courses, in cars that boast full damage modelling. It's one of those racers that straddles the line between realism and arcade feel, similarly to the mainline DiRT games.
Head over to Humble Bundle and you can grab it for free over the next couple of days. It's to celebrate a big Codemasters sale they're having, so be sure to check that out too.