Before buying a 3 series or any BMW diesel look on one of the BMW forums and look for swirl flaps,these small units built into the inlet manifold have the power to destroy engines when they disintregate,they are best removed and blanking plates fitted.BMW have regonised this as a major problem but be aware of it before you chose. Effects vehicles from 2000 to around 2007 but reports of failure on newer vehicles is being reported as the modified swirl flaps are not much better than the old ones.

Edited by Andy Bairsto on 29/11/2010 at 19:31

Roly - the only answer is to see which you prefer by means of a long test drive in each. I so wanted to like the 3-series (320d Touring - same as the one you're looking at) but:

(a) I didn't like the notchy manual gearchange, and the automatic kept making me think of the performance that I was missing;

(b) I'm 5' 7" with an average sized body but shortish legs, and I just couldn't find a comfortable driving position: to depress the clutch fully I was too near the steering wheel. (It's the same in my old Z3, but this is a fun car and it doesn't seem to matter as much as it would in an everyday car).

Also, it depends on your style of driving: a BMW is at is best when pushed, whereas an Audi suits a more relaxed style of driving. Of the two I'd have the Audi (although I'd look closely at the offset pedals on the new model which road testers keep complaining about) - but I can't resist mentioning that my Octavia estate with the 2.0 TDI engine as in the A4 is £7,000 cheaper. I love Audis but I couldn't afford another 2.5 TDI (2.7 now) and for the 2.0 I just couldn't justify the extra cost.