Its a loose, loose situation.
I do like the Audi A4 estates but they are mega money for the age and mileage but they hold their money really well as reflected in current used price market. I cant bring myself to fork out 17k for something that has 60k on it and is 4 years old.
On the other hand you look at mondy's and insignia's that you can pick up for 17k which are less than a year old but you know in 5 years time you will have lost a shed load in depreciation and would be lucky to see a return of anywhere near 10k.
BMW 330d estates are sought of in between the two but I think I'm bored of BMW now. Plus I'd probably be looking at either down grading or getting one that is older than the one I have now.