Download (http://gtag.gtagaming.com/forums/index.php?automodule=downloads&showfile=55)
After pressing F2 to save your replay, wait at least 8 seconds before pressing F4 to save the replay (the mod will actually force you to wait, so no worries, eh?). The replay will be copied to a new directory in "GTA San Andreas User Files".
It is also reccommended to not press F3 too soon after pressing F2 as well, as due to a bug in the game, the replay will attempt to play without it being fully saved...
You can save up to 9,999 replays (good luck on tryna achieve that limit). From "1.rep" to "9999.rep".
This was made a while ago, still, I've made discoveries since then which may allow me to extend it's capabilities, so an update might come when I have the time.