It's usually the name that gives it away. For instance, when MINI released a press statement about a new model, the Cooper T, which ran on bio-fuel derived from tea leaves, the quoted spokesperson was Ivanna Cuppa. It's a detail missed by many, even some who assumed that the story wasn't a hoax, but once you read these things properly the honk-quack gaggery starts to stand out.
Sometimes, the details are a little more subtle. For instance, BMW issued a release that claimed it was installing a hurricane-force fan into the heating system of the car that would blow high-speed air into the cabin, making it feel as if you were driving faster when you were actually being sensible and legal. Not a bad idea in and of itself, but the giveaway was the name of the system - Forced Induction Booster. Fib. Geddit?
I know, my sides, right? To be honest they're not actually all that funny, most of these motoring April Fools. Opel's Cocacabana concept, with its beach sand in the footwells and natural grass finish for the seats? C'mon, who took that seriously?
Or a Skoda Yeti with a fake fur exterior to match its legendary namesake. To be honest, we've seen dafter exterior finishes you could actually buy (step forward Mansory), but even so.
SEAT's PR people, Spanish jocularists that they are, have had a couple of howlers too. How about a Leon Ecomotive that could go for 10,000km between refills? The only catch was the 'optional' 545-litre fuel tank. Better yet was the Ibiza hybrid that could deploy a small windmill on the roof at motorway speeds to send charge to the batteries. People still claim to me at parties that this is an idea that would work...
Hyundai proposed an i10-based Popemobile to better fit the Pontiff's motoring needs in with a post-recession world of austerity, while BMW (again) suggested that the regenerative braking system of its X6 SUV could detect when a naughty dog was about to wee on the wheel and deliver a small but sharp electric shock.
Kia once suggested that you could buy your new car as a flat-pack and build it yourself (the i-Kia of course) apparently not realising that Caterham had actually been doing this for real since the seventies. Kia also gave us the (not at all real) Kia Wii, which replaced the steering wheel and pedals with the wireless controllers from Nintendo's gaming system. That actually sounds uncomfortably close to reality these days...
Mercedes-Benz, which you might assume would be a company entirely devoid of a sense of humour, once tried to convince us that they were going to put an AMG 6.3-litre V8 engine into a Sprinter van. That was actually kind of a cruel joke - we would have loved that and there was a precedent - Ford's Transit-based F1-engined SuperVans anyone?
Speaking of Formula One, Red Bull once tried to convince us that it would fit a race car's steering wheel with a small screen to allow drivers to read and send Tweets during a race. Again, we'd actually quite like to see that...
Will there be any stand-out gags this year? Will there be any that are genuinely rib-tickling or are we in for another year of car makers trying to convince us that they're actually really cool and funny? Let's see...