Anyone out there have/used one of these rear hatch vents? http://www.mamotorworks.com/corvette-c4-rear-hatch-vent+1984+1996-1-163-772.html  I'm thinking of picking one up to increase air flow in the coming hot months.

Yep, I have had one for a few years, never go thru the summer without it. Really cuts down on cabin turbulence, especially with the top off. Also great when you park for the day at a car show or Carlisle, keeps the heat buildup down. You won't be sorry.

Any worry leaving it on and parking it?  ie not an easy break-in for a thief?

I to had one for my old coupe. Also cut down on the wind noise while on the highway. Made for a much more pleasant drive. Not worried about break-in just really worried about if it was going to rain!

Unless the thief has the roof removal tool or a hacksaw, they'd have to break the hatch window to get it open. It only takes a minute to put it on or take it off, so it's easy to remove if you park it somewhere you would worry about.

Well then it sounds like a no brainer! I've got one ordered and it should be here soon! Thanks for all of your help!

works well, does the job it was intended for, you can use it with the VATS, easy to install, inexpensive......what are you waiting for? lol 

Worth the money spent when you take the top off as it really cuts down on the turbulence in the cockpit while your crusin!. Just minutes to install and remove.

Had one for years! I agree with everyone above. The only negatives, louder exhaust sounds, water from rain if you get caught by Mother Nature. 

A great investment and worth every penny!

I see that you already ordered it, so this is my two cents, as late as it is.
It is a great investment... but I would have recommended you to spend the extra money and get the "quick release" version. The one you show in the link may take only a minute or two to put on or take off, but the quick release one truly takes only 5 seconds or so. Maybe more than 5 seconds the first couple of times, because it looks like one of those hand puzzles.

--Rich