Couldn't find what I wanted in a catch can. All were too big, too small, not filtered, too finely filtered, connections in odd spots or silly angles, too expensive or plain old looked like s#!t.
Modified an alloy overflow with a sight glass which used crappy push-loc connections with some plastic tube that's used on bloody fish tanks.
Never seen one more than a month old that hadn't turned so brown you couldn't see what level it was at.
Changed that to Orings and some borosilicate glass (Pyrex) cut the back open and put some mesh in to retain some SS scourers and soldered it back up- killer!
Went to put it in the car and it was too bloody big!
So I made my own. Second attempt at aluminium soldering...
Filtered, baffled, recessed borosilicate sight glass, drain plug, removable from the bracket with just a clip, and hose barbs right where I wanted them.
Started with a bit of aluminium sheet, trimmed it up, and bashed my sight glass section into it.
Got it pretty even first go. Rolled it up and soldered it before realising it was about the same size as the last one that was too big so I cut out a strip 2.5"ish and soldered again.
But wait, there's more...