Occasionally I have run rides for my bike club and parking is always an issue for those that drive to the start. When we've expected more than a couple of cars, I have made a formal request at a local church to park in their lot, which has never been denied. But I ask every time, and never assume that it's ok. It's not an issue of having enough room for a couple extra cars, it's asking to park for approximatley xx cars for 3-4 hours. They always tell us which corner of the lot to use, and we are careful not to leave behind any trash or debris. So far they have been very willing to have us but looking from their point of view they have every right to refuse - and can always cite insurance if nothing else to dissuade us.

If you had a friend that was a member of that church, maybe they could put in a good word for you and your request.

Good luck.