Posting to add useful information for anyone wondering about the car wash mentioned above:
It has a sign saying "Rocky Point Car Wash", and the self-serve washing stalls operate on tokens.
To buy tokens, walk just inside the gate to the storage unit area (like 5 steps); to your left will be a door that leads to a small office. Inside the office is a man (usually a short señor) who sells the tokens. They are 10 pesos each. You need 2 tokens to start the washing machine: 2 tokens yield 5 minutes of use.
The señor doesn't speak english so spanish and/or awkward pointing and gestures will be required if you aren't comfortable with spanish
