Just sailed through its NCT; that's Irish for MOT ;) - never came close to failing.
Spent under €800 (<£550) in over 18 months of ownership.
Great to drive. Lovely on motorways and dual-carriageways. Handles very well on the back roads too. Good road holding.
Fairly economical for a big car - I get 36mpg on average, although it's rated at 34mpg on Parkers.co.uk. An Accord 1.8 only gets 31mpg.
Big, big boot (although I did have a problem with the lock getting stuck shut - cheap to fix).
Passengers comment on the room and comfort in the back.
My mechanic says it's the only decent French car he's driven / worked on! :o.
I didn't service the car for over a year, but it didn't seem to do it any harm, as far as I can tell. Won't be leaving it as long next time though.
One complaint I have about my trim is that I'd like air con (initially steered away from it because of extra servicing costs and fuel consumption / loss of acceleration). Also, it has a boot changer 6 CD system. I wish it had a CD player in the centre console instead - so I could change it for a MP3 / CD player!
Honest John (honestjohn.co.uk) was right! The 1.8 doesn't have a lot of oomph. My advice: get the 2L at least - or go for the 2.0 / 2.2 HDI. I gaze enviously across at the HDIs as I tear past them on the way to work (for some reason, people seem to drive them slow, even though they have better performance than most petrol versions! If I had one I'd put it through it's paces...).
Steer away from the 406 Coupe - it was lovely in its day, but I think it's aged more than the saloon. Considering it's a 3L engine, you'd expect better performance too.
I like the look of the car. I like the look of the 407 too, but it divides opinion, whereas everyone I know seems to like the 406's shape. That Pininfarina styling <sigh> has aged well.
Perhaps I got lucky, but I think that the general opinion that the 406 is unreliable is unjustified. Mechanically it's very sound. The electrics are, shall we say, a little buggy. The trim is nice, but a little flimsy. Apart from that, I think it's a lovely, reliable car... so far. Parkers gave it 4 ****'s (that's 4 STARS, by the way) for pretty much everything - including reliability.