Anything less than the 320d highline isnt worth it from the 3-series line up. There is barely any kit on offer on the lesser models.
And seriously, the days when Diesel meant low performance and refinement are long gone. I would strongly suggest to him to TD the 320d highline, it feels more torquey than my 325i
.
If he can wait, I would advice for the new A4 as well, it looks awesome, and im sure it would be a scream to drive. Not to mention the fact that Audi does the best interiors.