Rattle only with top up?
 

It really is affecting my quality of driving experience, and not to mention the wife pointing it out for me. :/

Only with top up. Sounds like plastic to plastic or plastic to metal. Soft, vibration noise. Comes & goes with every bump. Only at 25-30 mph and on smooth surfaces with minor roughness to cause a small vibration. With top down, silent. I would certainly still hear it if it was still doing it.

I think I hear it best from my left ear beause of the opening to the compartment where the top folds into? '04 S so I have the liner and glass window.

Thanks a million!!!

I'm unsure where you are saying the noise is coming from. Mine rattled when I got it but that was because these were missing from the two lugs that slot into the windshield:

PORSCHE Boxster Boxter Hard Top Hardtop Lug Covers NEW | eBay

Are these rubber lug covers specific to just hard tops? I don't think my 97 soft top has them on the lugs, but if they're missing and supposed to be on, it would surely solve some of my rattling problems.

Timco: I have a very annoying squeak/rattle thing going on behind my left ear as well and it's noisy top up or top down. You may want to do what I'm going to do when I have time. Get my wrenches out, put the top in service position, and start wrenching on every fitting I find to see if a bolt or nut is loose... and get those lug covers if your car is missing them. Cheap fix.

I read this at work in a rush and thought it said hard top. Sorry about that, these wont fit a soft top.