on
www.ukmotorsport.com look at your local regional association for smaller events.
So for Warrington try the Association of North Western Car Clubs :
www.anwcc.org
The regional association will have a calendar on their website. Its aimed at competitors but at least it gives you an idea of what's on & where.
so for the north west I can see that today (Sunday 6th April) there's:
6 Apr - Jubilee Historic Rally (National B) Historic Road Rally (Yorkshire) Ilkley & DMC -
6 Apr - Lookout Stages (National B) Multi-Use Stage Rally (Melbourne Airfield, Nr York) Trackrod MC
6 Apr - Loton Hillclimb (National B) Hillclimb (Loton Park) Hagley & DLCC
6 Apr - Jubilee Run (Closed) Touring Run (Yorkshire) Ilkley & DMC
the contact numbers & emails listed (I deleted them for display here) will probably be those for the club secretary or the Event Secretary who deals with competitor entries, it also lists the local motor club organising the event, for which you will be able to find other contact numbers & websites from the association website's list of member car clubs.
Individual local car club websites also often list events in the area that may be of interest to their own members to enter, so worth finding the local clubs and seeing if they run website event calendars