Hey Guys, I know the general consensus on additives on this forum, but I figured it couldn't hurt to ask. The mustang has a small crack in the plastic part of the radiator, only leaking about 1/2 quart every couple weeks, so it's not that bad yet. Are there any reputable stop leak products? Do they work on plastic? Or should I just save up for a couple months and hope the old rad hangs on for that long?