I realize CA is a land unto its own...but locally I have to pay hefty taxes to live in my home and indirectly my tenants pay me so I can pay taxes ....so I am far from a fan of mobile housing not paying taxes for City or school .
And if a church is involved in uses of its parking lot for purposes not directly connected with practice of its religion, perhaps local authorities should investigate putting church parking on tax rolls ( church parking lots used just for church purposes are exempt via a state Supreme Court decision in my state ..but that's far from Ca.