Our church is holding Vacation Bible School in July. Is it ok for us to place flyers on car windshields in the parking lot outside the store or do we need to contact someone to get permission first?

Well, it does not hurt to ask the owner of the lot

I would say yes to be on the safe side

Yes you need to contact someone to get permission first

Not really sure, but I don't think they would mind if you did that. As long as it doesn't stick to the windshields I don't see a problem with it