i shoulda checked this site as soon as the idea hit me, always funny but rarely useful
http://www.webehigh.com/city/detail.php?CITYID=2085
some choice bits from the article;
In La Perla, you RARELY see any police. And when you go down there, the people will shout to you "weed, coke..." as if it was legal. They sell from shwagg to "creepy" which is like skunk... Another place to go is any local headshop, and discreetly ask the guy for weed and tell him you are a tourist. But for the really good stuff (kush, haze and more), you need to know someone that knows his stuff or somebody."
but later
our best bet is to go to La Perla and buy something there. The downside is that because the police rarely never goes down there, they are almost everyday in the only entry/exit of the place checking for whatever enters and goes out. So if you are going out with, lets say, an 1/8 of weed, you better stick it in your butt-chicks so that the police cant find it if they, for some reason, check you.
so the place to avoid cops, you can't leave without seeing them.
but this part of the article was very interesting
They don't sell rolling papers ANYWHERE in PR, all blunt or blunt rolling tubes. So, if you go, and you do score, bring your own papers with you. Most everyone I ran into, was willing to help me score some bud. Very easy to find.