Ben: was thinking about this a bit last night. What to do when electronic devices get wet...
Common wisdom says:
1) don't try to turn it on yet...
2) instead, put it in a big bag of uncooked rice for several days
Hoping this all goes well!
Seriously though: I'd be thinking about finding an enclosed place to put it where you could run dehumidifiers for a good while. But what do I know - I'm sure there are experts out there on how to deal with flooded cars.