I'm sure if you just typed in "Junjou Romantica Drama CD Download" into your search browser you could finds places that let you download or listen to the files. Just have to dog a bit. :)) Nothing is impossible to find!
I got mine from here: http://aarinfantasy.com/forum/ You have to sign up and such, but there is so much to download there. It's totally worth it. They have manga, anime, drama cd's, games and much much more.