That letter I sent to Modo the Car Co-op two days ago? It worked! This morning I received a phone call from Nicole, the boss of customer service. She offered a sincere apology (along with a $25 credit for car time) and assured me that they would certainly make an exception to the crate policy in Freddie's case.
When I wrote my letter, I was kicking myself for failing to get the name of the snarky rep I'd spoken to, but now I'm thinking it doesn't really matter. Who knows what was going in her head/life? If all Modo's phone staff get a message informing them about service dog exceptions*, then the important goal will have been achieved.
*While it's true that many service dog handlers don't drive, I suspect there are increasing numbers who do (people with autism, PTSD, T1 diabetes ...).