Hi Michael
I bought a 2003 JTS wagon in Sydney last year (Gabbiano metallic blue with black leather) had 89,000 on the clock from a dealer. Paid $19,990 for it. With the wife we had a road trip back to Hobart down the coast. With the back seat down we fitted our luggage, two surfboards and stuff (wine, lamps etc) we bought on the way down. I know the 159 is longer, but from perspective I can fit all I need into the car with the back seat down. I even can get my mini mal board (7''

into the car. Skis are no problem, with the split rear seat.
From my experience so far, it now has nearly 95,000 on the clock it runs like a dream. Maybe I found a really good one. The car was a one owner from new with full Alfa dealer service history. The only minor niggle is that on occasions I get a small squeak from somewhere in the front suspension, I suspect I need to change a bush. I have had some discussions with other forum members re 156s and the general consensus is that the front suspension is a little soft (I agree) and hence best to change the shocks to either Konis or Bilsteins. One can also change the springs (Eibachs have been recommended). Apart from that the key to remember is to always keep an eye on the oil levels given the variable valve timming. I have heard complaints re trim quality, electrics etc but I havnt had such problems. Mine has the Bose hi fi upgrade and the sound is superb !! I recall recently seeing someone talk about a problem with their temperature guage and this was traced to the thermostat.
As to the 156's fuel economy, it is excellent both around city and highway mode. I think the books talk about 6-7 L/100km range. I can't quite remember the actual figures. Basically it is cheap to run. I personally reckon the sportwagon is one of the best looking modern wagons. If I were to change it, it would be only for a 159 sportwagon and there you have the choice of the 2.2 JTS or V6.
I don't know if there is much difference between the 2002 and 2003. It could be that the 2002 had the Twin Spark and the '03 the JTS engine. My mechanic highly recommended going for the manual over the selespeed, which is what I did. I recall being advised that the JTS engine is the better choice. Perhaps more knowledgeable 156 owners have differing views??
Prices from what I have seen seem to vary a little for 02 and 03 cars but you should be able to find one for between $16,000 to $22,000.
Goodluck in the hunt for one.
Cheers Dave