The Plasticos Iga Mexican release of G1 Windcharger is known for one standout feature, its robot face is not painted shiny silver like the Hasbro Takara version which is the most common, in fact it has no paint application on its mouthplate at all. Hence "grey face", or in reality "unpainted face". This toy would have been released in Mexico on a Spanish G1 Plasticos Iga cardback in 1985, and also exported into many European countries.
Typically, unless you can actually see the robot face and assess whether or not it is painted, it can be very difficult to spot one of these Mexican Windchargers. The red plastic is a little more matte than HasTak versions and the Autobot sticker on the chest is a little off centre relative to its silver background. A common series 1 Mexican minibot factory Autobot sticker trait.
You may be able to tell from this picture that the red plastic is a tad different to normal Windchargers - it's lighter (typical Iga). The moulding on Iga minis is never quite up to the same standard as the HasTak releases either, usually rough around the edges, slightly ill-fitting (see arms above) and generally looser.
Comparing Iga Windy (right) side by side with a very early pre rub Windcharger (left) and a normal rubsign Windcharger (centre) shows up just how more refined the moulding is on the torso details for HasTak specimens. The chest sticker quality is notably worse too. Interestingly (debatable) the horizontal gap moulded into Iga Windcharger's belly immediately below the Autobot symbol is of the thinner variety like the pre-rub 1984 Windcharger moulds as opposed to the 1985 common moulding.
The above two photographs show off the unpainted face on the Iga Windcharger and the lower quality printing on the factory Autobot sticker on his chest a bit more clearly. I'm all for Windcharger variants and have had virtually every single one I have ever heard of in my collection at some point apart from the Optimus vs Malignus Brazilian pink/blue one, yet strangely I think this Mexican one with the seemingly normal paint job with a solitary stand-out feature has great appeal. Subtlety is not always a trait one associates with Mexican variants, but it's something the Iga Windy exhibits, and it's all the better for it. I have only seen one carded one in 15 years of collecting - you can find it here.
All the best