I'm going to brew one of these soon, I too have had difficulty finding proven recipes,etc.
Here's some info/quotes from the babblebelt:
"Biere de Mars translated means "Beer of March" and from what I've read, it was produced in the spring months using the first harvest barley/grains which brewers claim to be the best quality ingredients for brewing. So, the beer of March is regarded as a top quality brew that is brewed in spring with fresh, newly harvested ingredients and is meant for summer through fall consumption. It is a sub-style of Biere de Garde except is usually a bit more hoppy and bitter. Farmhouse Ales has some descriptors about the brew itself."
(this guy knows his stuff, trust me) -> Al B: "I'm going to try WL Antwerp when its out soon for a Biere de Mars.... For an extra Spring-like quality, I'll use 30% dark wheat, some Munich + aromatic and cold-condition over the Winter."
My friend has the Farmhouse Ales book, hopefully he'll let me borrow it next weekend so I can read up on this style and how to brew it, I have that yeast on hand( VSS Antwerp)but haven't used it yet, so I'll probably try something like he describes, unless there's something interesting/different to try in Farmhouse Ales.
Maybe we could brew something similar but with different yeasts and see how they come out. I probably won't be able to brew this until early January when I get back from holiday vaca'. But it will be brewed in one form or the other, don't worry.