Move between MIA terminal F and D
 

I'm leaving MIA in a few days by VS Upper Class and know that the lounge in F terminal/concourse is crap... Ive got a UK amex platinum card so assume I can access he Centurion lounge in D... Is it possible to do this airside or do I need to enter and exit security etc... If so is it worth it or bit? I was hoping to get a shower before leaving as it's a late flight and I'll have been out in the sun all day.

Just a follow up in case anyone missed this who might know the answer as I'm flying tonight :)