Re: 156 2.5 v6
I have one of these that I bought last year.
i) Suspension knocks and squeaks. Mine got to 70k before it needed front end work, and is expensive to rectify. I did it myself for £300, but this is a long task! Parts are reasonable but it all takes a load of time.
ii) Bent sills - people jack em up in the wrong place when they get flat tires. Bends them horribly! Get on your knees and look at the sills and floor pans!
iii) Rust. Yes, rust. The car has a foam underseal like stuff on it that makes the car look mint and fools people into thinking corrosion is not a problem. But..... the foam underseal gets loose, water gets underneath, and the rust can be scary! "But 156s don't rust". This is said by people who don't get under their cars! Check the wheel archs and underneath for the brown stuff! 156s fail MOTs on this.
iv) Bad/inconsistent tire wear - means something is wrong!
v) Oil level. All Alfa owners know how much their cars use, if the seller of yours says "none", or doesn't know, walk away! The V6 is the least offender it seems, but you will still be checking the dipstick and topping it up at set intervals. It is not leaking or burning it, it is meant to use some!
vi) Consistent power delivery - the V6 is smooth, with no stutters or steps as you cain it. Anything wierd here is expensive - MAF sensors are over £150 if you need one.
vii) Cambelt cambelt cambelt! These engines are very reliable if the belts are done on time and properly. The car may have the self-destruct waterpump fitted - make sure the metal version is fitted as a replacement. Loads of V6s I looked at had an invoice in the paperwork for overheading or head work where the pump had failed or the belt snapped. The belt is gonna cost nearly a grand to do properly, and if you are thinking "go to those blokes who do it for £450" then this car is not for you! The people had seen theirs snap said stuff like "I thought it would be alright", or "I didn't want to spend the money".
Hope this helps! I started out wanting one with the leather and big wings, but hated the feel of the seats and ended up getting a nice velour interior instead without the wings and body kit!
Get one, you'll love it, and the pain of 22mpg soon goes away...