I'm not sure what you are expecting of such a meeting ? Just seeing each-other cars on a parking ?
I've organised some meetings for the former TT-club Belgium. The day started around 9 o'clock with a croissant and a coffee at the meeting point.
In de morning, we where doing some site-seeing till noon.
After a nice lunch, we usually visit some nice place.
One of the simplest meeting in winter was a guided visit of "living tomorrow"( http://www.livingtomorrow.be/
) followed by a nice lunch at "Drie Fontijnen" ( http://www.dedriefonteinen.be/
Both are just near the Brussels Ring.