The gaping-mouth front of the 407 still comes as something of a shock as the saloon range moves into its second year of UK sales, but somehow less so in the case of the more recently-introduced estate version. The SW's shape is so satisfying - the opinion of several friends rather than just myself - that I can't help wondering if this was the car Peugeot had in mind all along, with the saloon being a design afterthought even though it was introduced first.It also occurs to me that some people might buy the SW simply because it looks better than the four-door. The more likely reason, though, is the increased luggage space. The saloon manages 407 litres, but the SW starts at 430 litres and extends, if you fold the rear seats and cram the thing to roof level, to 1365 litres.There's a great deal of room for front-seat occupants too, but the folk in the rear don't get quite such a good deal. For me, the back seat accomodation is limited in terms of both legroom and headroom, which comes as a bit of a surprise in a car as large as the SW. It should be possible to carry four adults a very long way in considerable comfort, but only if none of them is much more than six feet tall.The car tested here is the SE Luxury Pack HDi 136. We'll get to the HDi 136 bit shortly, but first a word about the trim level. It's the middle one of five in the 407 SW range, the others being (in ascending order) S, SE, SV and Executive. The Luxury Pack adds leather/cloth trim, electric seats and rear parking sensors to the SE specification, which becomes as a result almost identical to that of the SV - the only differences are that the SV has velour trim and a CD autochanger.Reasonably enough, in their HDi 136 forms the two cars are priced identically, at £20,050. That's slightly more than they were when the SW range was introduced; since then, cruise control has become standard rather than optional on all 407s, which has led to a slight price increase and a step up in insurance rating from - in the case of the test car - Group 10 to Group 11.Our car also had a couple of options fitted. The metallic paint costs £325, and would probably be worth considering to keep up the residual value, while another £400 gets you the Security Pack which consists of rear side airbags, pyrotechnic rear seatbelts, side window sunblinds and laminated side windows.So, about that engine. It's the very familiar and very good two-litre HDi turbo diesel, providing in this application low noise levels, fine fuel economy and impressive mid-range pull. You can have it with a Tiptronic automatic transmission, but I quite liked the six-speed manual gearbox of the test car, which has a better shift quality than I've experienced in other Peugeots.The HDi makes the 407 a relaxing car to drive, and despite the temptation of the various petrol units and the less powerful but still useful 1.6-litre diesel, I suspect this is the engine I would choose for myself.I'm not so sure about the 17" alloy wheels, or more specifically the 215/55 tyres which clothe them. The 407 is not especially nimble, even when you take its size into account, and the low-profile rubber gives the chassis more work to do as bumps and humps in the road try to make their presence known to the driver and passengers.While there isn't much you can do about that, you can certainly make a big difference to the way the SW tackles twisting A-roads, for example. It can waft over them very smoothly, but only if you work hard to make sure it does. If not, it lurches. This makes it a very good car for honing your driving skills, but for slightly more than £20,000 I'd rather some of the effort was being done for me rather than by me.Overall, though, this is an impressive contender, with many genuine qualities lying beneath that handsome exterior. Engine 1997cc, 4 cylinders Power 136bhp Transmission 6-speed manual Fuel/CO2 47.1mpg / 159g/km Acceleration 0-62mph: 10.1 seconds Top speed 126mph Price £20,050 Details correct at publication date