Rusty exhaust smell inside the cabin – should I be worried?

[loganhughes]

I've been noticing this weird metallic, almost burning smell coming through the vents whenever I'm sitting in traffic for a few minutes in my 2013 BMW 328i. It goes away once I start moving again but it's honestly starting to give me a headache after longer drives. I crawled under the car and saw some surface rust on the exhaust pipes but nothing that looks like a hole or crack. A friend who knows more about cars than me said it could be a tiny exhaust leak before the catalytic converter letting fumes sneak into the ventilation system, and that carbon monoxide is no joke. I've been looking for a shop that does reliable exhaust repair abu dhabi drivers trust for European cars because I don't want to take any chances if it's actually dangerous. Has anyone experienced this kind of smell and found it was just a loose heat shield or a torn gasket that was cheap to fix? Or am I right to be paranoid and should get it checked immediately?