Ah...I've just looked. Can't see a stop in CD, unfortunately. East Grinstead or Pease Pottage would appear to be the closest. Oddly, we don't seem to run any buses from Crawley. I guess that must be to avoid offending Crawley Town.
Does Crawley Down feature on any of the Seagulls Travel coach routes? If so, I'd have thought that would be a good option, especially for midweek games. They seem to have pick ups in most towns & villages around the county these days.