I agree but disagree. All the "best" competitions are crap but I disagree as to why a forfour doesn't win it. Here's why it doesn't.
Fortwo owners, more often than not, are freaks. They think their cars look good if the plaster them with terrible vinyls or hideous paint jobs.
Roadster owners are (generally) wannabe sports car owners, usually midlife crisis but without the cash. They mod the hell out of the Roadster to get extra power in an attempt to claw back their age and hair line.
Forfour owners, by and large, a very normal compared to "other smart" owners because the car is more normal. They don't do the silly paint and graphics, generally they don't mod for mental power. Normal cars attract normal owners and normal owners don't do things to their car that would win a smart event. The judges at these events are expecting fluffy toys, horrible paint and mismatched vinyl, they are also expecting thousands of pounds worth of mods which just aren't available for the forfour.
As for "best kept". Fortwo and Roadster are smaller cars so less likely to scrape the paint and those car owners are more likely to change panels. I've never known a forfour owner to change their panels.
Personally, I think that not winning these competitions is actually a win in itself.
Use the system, get a decent parking spot and represent the forfour community.
I'd still suggest that forfour.co.uk had their own stand. That's parking for 4 of the best cars we have on the forum.