I run TurboRenault with four other chaps. We work hard to drive traffic toward the forums, and leverage social media to do so. You HAVE to engage there as its just so popular and commonly used. We have a strong forum thats grown hugely in the last 3 years since it founded. We also offer a place to live for all the legacy forums that were killed off by declining numbers and social media, so currently we are TurboRenault, plus the legacy 21 Turbo Owners Club, Retro Renault forums, Renault 5 Turbo and Gordini forums and a few other bits. These mergers boosted our user base, archived the content of the merged sites for future reference and put it on a modern XF platform thats pretty shit hot as far as forums go. On top of that we cater for all models, as we felt model specific will only ever be a shrinking scene
We also adopted the "Free forever" mantra, there are no subs or membership you just register (you can even log in with a Facebook account for super laziness) and post away, and we have zero adverts, because again, thats the only way to compete. I don't go on PistonHeads any more because the forum functionality sucks by comparison and the adverts piss me off - same for many sites now. We try and provide the ideal - Free to use, no adverts, no power crazy opinionated mods. No decisions are made without 3/5 team members agreeing. We do easily self-sustain though, none of us need to pay to keep the place running.
I say the above because as a paid, model variant specific club, this place is so limited on user base it puts itself at risk. You are lucky that the cars have developed a cult status which will likely see it survive for quite a while yet - unlike the 21 Turbo and I watched that club decline to a rarely-visited nothing. Its part of the reason we kicked off TR.
James if you ever need an "Out" we'd quite happily on board you guys and give the Vee its own subsection. I know you're going to tell me to get lost right now

but just know the option is there.