Can I make an alternative suggestion, one that's perhaps more radical? Ditch the sub-forums altogether.
If we had two main forums, National & Local, then a sub forum in each entitled Convoys, we could reach a much bigger market. National meets will sell themselves, you could happily sub forum out each even if you wanted. What I'm talking about helping really is the local ones.
If we got REALLY strict on thread titles, this would be very easy to do. I'm thinking something like this:
1. ESSEX - Pub meet at The **** Inn, Tiny Village, 25-4-16
2. YORKSHIRE - Run out across t'moors, Even Tinier Village, 17-7-16
3. SCOTLAND - Haggis eating competition, Hamlet Of Four Men & A Sheep, 3-11-16
...and so on. Very easy to scan by eye as to events local to you (hell, even the search function would work perfectly with that!), keeps everything so simple, but allows everyone to see what is out there and when. Keep a sub-forum for convoys, with the same naming scheme. If people don't name their threads properly (and they won't!) then it's not too hard for a mod to change. If you want a volunteer mod just for that task, then I'll do it: You can set permissions so I can only mod in that forum and keep me barred from the main mods forum.
Biggest issue I can see is with potential meet discussions, but that could be done like so:
1. LONDON - Potential pub meet, June/July 2016?
2. CORNWALL - Drive out, weekend of 23/24 April 2016?
Again, a question mark should always be added. Easy as that.
I just feel we're not really making the most of the events section, and it's too convoluted for it's own good. So yeah, merge what Grundy said here and I reckon we could sort this out easy.