The "M" means Mexico. The "Z" means year 200x, the "4" makes it 2004. There are some quality control differences between the MiMs and the MiAs, but if you're on a budget, it's my opinion you really can't go wrong with a MiM. I really feel I got a bargain. I prefer this particular MiM over the latest Standard MiM I test drove at a Guitar Center, and even over the American Standard that sold for $999.99. Keep in mind these are very subjective observations. Overall, I believe this is one of the "best bang for your bux" deals I've gotten in quite awhile.

For anything I may have missed here, you may want to see my post in the Gear forum:http://www.guitartricks.com/forum/showthread.php?t=24973&page=2&pp=10

Some helpful info:

Dating your MiM (has links to MiAs also): http://www.fender.com/support/mexican_instruments.php

A very good article by an Ebayer: http://reviews.ebay.com/Buying-a-Fender-Stratocaster-A-Guide-for-the-Novice_W0QQugidZ10000000001650626?ssPageName=BUYGD:CAT:-1:LISTINGS:5

Strats by Year:http://www.stratcollector.com/scn/base/84.html

If you look at 1984, the second picture of the brown Strat, that's what my Strat looks like.*

PS: I should add that the MiM necks are made in Corona, California and shipped to Mexico. The MiMs are made of lighter wood also (I always confuse alder and ash, so I can't say which wood the MiMs are made from.) I was expecting a real lightweight compared to my MiA, but the MiM feels just as hefty. Strats are/were made in Japan also (MiJ/CiJ- think the "C" means "Customized for")- I believe I read somewhere the MiJs are now made for Japanese consumers now only, but not really sure. The MiJs are supposedly superior to the MiMs.

*My Strat looks looks like the the one in the picture, but doesn't have the marble finish. Mine has a natural wood finish. I just wanted people to see that the output jack is flush with the body, as opposed to it being recessed. Also, the neck plate on my Strat says "Fender", and there's a hole in the back to gain access to the truss rod; you can adjust the rod from top and bottom; Fender calls this the "Bi-Flex" truss rod system. This is proving to be a real bear to do my setup, especially since I put 12 gauge strings and tune a quarter tone down. Right now, I'm having a tough time getting the action lower- I may have to bring it to a professional tech to get it right. In the meantime, the high action is good for getting my fingering spot-on, and doesn't leave room for getting sloppy.