I used to be involved in the promotion of one of the stock car organisations and used to get onto both local BBC and commercial radio stations on a fairly regular basis. I also know that at least two other local promotions were also successful in getting on the local radio stations. Providing you didn't just make it a free advert and gave them a story about local drivers with reference to recent results, then even the BBC stations would accept mention of forthcoming meetings where the drivers you had mentioned would be in action again.
Speedway would be a lot easier with the team format at most meetings meaning you are automatically talking about something local even if the riders come from the four corners of the world. It does however mean you have to cultivate interest from one of the presenters and give them information on a regular basis. The promotion I worked for had two tracks in the same area so I only ever mentioned one track on the local BBC station and the other track on the local commercial station, that way both stations were happy to interview me every two or three weeks during the season.