I have seen many of the plugs for the open space behing the mag well for the Subcompact Glocks on the internet, some of them are shown as fitting flush with the bottom of the frame while some stick out.  Does anybody have a link for a place online that sells the plug that fits flush and does not require any modifications to the frame.  Thanks

Here you go buddy

Lone Wolf Plug M/26

The plug you need is the LWD-PLUG26 Lone Wolf Plug M/26 . That is the one that will fit the G33.

Although not technically a modification, you will most likely have to loc-tite or glue that plug into the gun.  Since the little Glocks don't have the lanyard hole to retain the plug, it has a tendency to fall out during shooting.  I put one on my G27 without gluing it, and after about 25 rounds or so,  and having to reset the plug after every magazine swap, I wound up throwing the plug in the garbage.

Those things are a gimmick and serve no purpose.  Not even to keep foreign matter from getting in that space.  The foreign matter still gets in from the top of the frame, and the plug doesn't allow it to fall out like it  normally would.

edited to add:  I did not have the magazine guide type.  Just the plug type.

I have heard that they fall out while shooting but was thinking of using it while it's in the safe or while being carried just to keep dust and debris out of that space.  Does anyone know if Glock has ever addressed the possible issue of debris collecting in that space?  BTW the only reason it's in the safe is because I'm carrying my G23 that day.  

Quoted: I have heard that they fall out while shooting but was thinking of using it while it's in the safe or while being carried just to keep dust and debris out of that space.  Does anyone know if Glock has ever addressed the possible issue of debris collecting in that space?  BTW the only reason it's in the safe is because I'm carrying my G23 that day.

Yes, Glock has addressed the issue.  They designed it without a plug so anything that gets in there can fall right back out.  

Quoted: I have the glockmeister in my g17 and it locks in pretty tight and hasnt ever came loose or fallen out.  We also have them in stock currently.  $7.00 Each....we also have glock mags as well.

The sub-compacts don't have the lanyard hole like the G17, that is why they are always falling out.