98, I don't live there but I travel to Miami a lot. And I've been there several times with my DS so I know all about what it's like in the clubs (strip and otherwise) if you're under 21. Pm me for details but here's a summary.
You won't get into any decent strip club in Miami if you are under 21 even being a beautiful woman. And your fake is unlikely to work. I know this for certain because I tried everything multiple times to get her into several clubs. But you can work at many strip clubs at 18. I'd suggest Tootsies, the site of the upcoming tuscl meetup. You just can't go as a customer.
The non strip club bar scene is just as bad. We tried all the tricks to get into some clubs but could not. In south beach, I even had a restaurant manager threaten to have me arrested for sharing my drink with her. I have no idea why Miami is so strict but I've taken her to lots of cities and have never had as much trouble getting her drinks and into clubs as I did in Miami.