As Stang8psi knows the smell can be bad from the breathers and with the cabin filter behind the cowl you can get the smell. Here is a catchcan setup i made for my car. Its 2 -10 lines that connect to each valve cover, then its a -12 vent line that vents under the car so you do not get any oil vapor smell.
FOR THE PEOPLE who get the vapor smell i recommend to vent it under the car.
FOR THE PEOPLE who get the vapor smell i recommend to vent it under the car.