I have a 2000 passat with the 1.8l-4 turbo. Right before my firewall, i have, from left to right, a black box, battery, and another black box. I was wondering which black box housed my cabin air filter. I'm going to change it so i need to know which one i'm going to be opening. Also, if anyone has changed their cabin air filter, which is a good one to get? I just spent about $300 getting my interior looking perfect, so i need something that will kill all dust entering my car. thanks in advance.