I bought a 2004 ZR last year and the top operates just fine, although the latch is a little noisy when it releases when opening the top. I thought that was normal until I opened the top on a 2007 and it was significantly quieter when the latch disengaged. Was that something that was improved upon in later models, or should mine be quieter? Is there something that needs greased in the latch mechanism on the roof, or the car?

 

My 06 is pretty clunky sounding too. The silver handle turns a cam that engages to locking rods on the ends. Pretty sure you can remove the 1st bow cover to adjust and lube. Mine is wind and water tight after my diy top a while back so I let it alone.
Good luck!

 

Not sure what constitutes "noisy" in comparison but, my 08' top is tight, solid and functions as designed with no offensive or unexpected noises. I do keep all [literally all] contact points front-to-back clean and well-lubed and I do it fairly often (basic maintenance in my view). As mentioned, maybe an adjustment issue. I expect it to "clunk with authority" to a degree when unlatching or latching.