rgr that. A little 4inch tall can 3" dia would have a lot more volumn than the one you have. it would be easy to make too. anytime your ready.
The only thing with that is your introducing moisture into the oil. The catch cans usually drain some nasty milky stuff, water/oil mixture. I never had one dump out pure oil thats for sure. As for place to mount it, in as cool an area under the hood as you can. Since it works on condensation, you want the can itself to be cooler than the shit flying through it, or it essentially wont work.