I guess RORO means that it's unprotected on the boat
ROROs are those huge slab-sided beasts that look like they should capsize in the slightest breeze. I don't know that they are climate controlled, but they are enclosed. They are what is used for new car deliveries; new car deliveries all seem to come through with protective temporary plastic sheet or shrink-wrap. A good expediter/shipper should be able to tell you what kind of treatment your Miata will get and may be able to help you with temporary licensure. In the U.S., the way that license plates/tags get handled and the associated paperwork for title gets handled varies from state to state. Maybe your seller can tell you whether the plates stay with the car or go with him?
might do some snorkeling though
Ah, yes,
this. I have seen party boats out there from Marathon and Key Largo. Shouldn't be hard to find one. I *tried* snorkeling off my friend's boat out there but there was a lot of swell that day and i was nearly killed by a rogue swim ladder!
It came to my mind that Jacksonville in north Florida is their biggest port for Atlantic shipping. I turned up
this link and it looks like Mercedes-Benz uses JAX as a port of entry, so maybe you can get a lift back to Bremerhaven or somewhere. Anyhow, it lists a few more auto shippers. Everglades? I don't have direct experience, but it is said to be unique (see it before it diries up and disappears) and you'll be in the neighborhood if going to the Keys. St. Augustine? Quaint. I took a boat trip from Daytona down to the Keys a few years back and I have to say I was impressed with the coastal waterway in North Florida. Once you hit the stretch from West Palm Beach to Key Biscayne, though, it becomes a PWC-overloaded madhouse until you get further south into the Keys and the more relaxed aspects resurface.