my old coupe had a 90mm pvc catch can mounted up near the passenger side headlight. I made it 2l capacity. you can sort of see it here - well part of it anyway:




best thing to do is fill the catch can with stainless steel wool wrapped in a stocking to help separate the oil from the air while preventing any swarf getting into the engine. also not best practise to have the breather entering at the bottom of the can.

it was in the car for years without any problems from hot oil.