Welcome to the club, Cameron.
I have an S Type Diesel [07 plate] which I have had for just under 9 years.
I have had a mild puff of fumes on the odd cold days, but as a retired person I can choose the time I start the engine.
Luckily, I was given some very good advice when I first got my car, and mostly about fuel and what best to use. I was advised to use Premium fuel preferably Shell and to ensure that the exhaust system should be kept clean. [I live 500 yards from a Shell Service station].
My exhaust is a stainless steel one and I make sure that I have a good additive to make sure the exhaust from engine to the fresh air. I sometimes get the yellow light which I cure. Three months ago the AA diagnosed the problem as EGR valves but my mechanic felt that the exhaust system should be cleaned which he got an expert to spend a day cleaning the whole exhaust system which made the engine like new.
I am not an expert for engines with my tool kit consisting of a lump hammer and a spanner, so I do feel that your knowledge will be very useful to many of our members, some of whom are very knowledgeable.
Enjoy you car,
Regards,
Peter.