Need assistnace from professionals

Hello there, I currently have a Land Rover Defender TD5, 4 door hard top. My land rover is experiencing some issues that I have never seen and am unsure how to go about fixing.

Recently after driving it around from 10-15 minutes I start to see fumes/exhaust leaking into the cab from the heater vent on the passenger side, it is bad enough where I can physically see the fumes coming into the cab. It just got warm so I am not using my heat at the moment and nothing SHOULD be coming from that hole.

If anyone has any information that might please let me know. Thank you.

You need to get the engine running and open the bonnet, and look at where it's leaking exhaust gasses from.

There are not loads of places. Just look.