I think the main principle is very similar in most european countries.
As long as the local club is a member of the national association,
and that national association is a member of the full scale motorsports association. Then there's no discussing whether it's a sport or not. It is.
Further EFRA and IFMAR membership is not that relevant when thinking about local community support.
And just bring a Ray Wood vid to show what it looks like, won't be a problem to see it's serious racing.
In my country the RC car clubs used to have their "own" national organization. We then got no economical support from the local community. But after we in stead joined one of two national full scale motorsport organizations in 2002, the clubs are now also automatically "members" of the national sporting federation. And is hence treated the same as for instance a soccer club.
This is THE key!
So now we can apply for funds for facilites etc. And the best bonus is the economical contribution for all young club members. This is #1 focus for the community!
It may be clever to contact one of the biggest & most successful RC clubs/tracks, and kindly ask if you could have copies/templates of how they apply for stuff. How things work basically. And saves you a LOT of time!
In case you don't get goodwill. And you know you should be getting it... then there's always the media

"Young kids have no place to race their RC racing cars..."
When/if you get a yes. Make sure you have long term (like 20 years+) rights to the ground where the track is! Otherwise you could loose the track again before you know it...
Best of luck!