Based on the entry-level 320d, the ES features 16-inch alloy wheels plus sports suspension, a CD player, an M-Pack leather steering wheel and a sports gearknob over the usual trim. But that's not all. It also has an interior storage package, consisting of armrest cubbies and under-seat sliding shelves.
Yet at £20,995, it costs £650 less than the car on which it is modelled - and that's without all the trimmings. Add those, and you're looking at a saving of nearly £2,400 - although we think extras such as front foglights, Dynamic Stability Control and a sunroof would have been more useful than the interior upgrades chosen.
But there are even more temptations laid on by the manufacturer. If you buy a 320d ES before the end of June, BMW will give you three years' free main dealer servicing on top of its standard unlimited-mileage warranty.
The overall result of these benefits is an attractive package that is sure to appeal to cost-conscious drivers. Yet is the ES convincing enough to lure buyers away from more traditional and established family favourites?
The logic behind BMW's plan can't be faulted. Thanks largely to its traditionally strong residual values, the 3-Series works out a whole 10 pence per mile cheaper to run over its first three years than an equivalent Mondeo - and that's before the cost-free servicing package is taken into account.
On top of that, the 320d is a fine machine to drive. The previous 2.0 diesel felt rather slow and cumbersome compared with petrol-powered versions of the 3-Series. But the latest incarnation - revised last year - is a real driver's car. It's quick, responsive and benefits from reassuring roadholding, while the sports suspension fitted to the ES gives the handling a further edge. In-gear acceleration is impressive, and the car cruises in near-silence at motorway speeds.
As with all 3-Series models, the gearbox, brakes and steering are superb, although the pedals are offset to the right and take some getting used to. Low CO2 emissions will please fleet buyers, while fuel economy is thrifty, even when the car is driven hard. BMW dealers are keen to do business on diesels as the company tries to raise the profile of its oil-burners, so be on the lookout for discounts and tempting PCP deals, which may be cheaper than less prestigious brands can offer.
Our few criticisms of the ES concern the interior. With a single-slot CD player and blanking switches, the cabin can't hide the fact that it's been created from an entry-level model. What's more, the standard Anthracite trim and headlining give the passenger area a gloomy feel, while the cloth on the seat facings is coarse and feels out of sorts with BMW's upmarket image.
Still, with the money you've saved on servicing, you could always specify leather trim. And that, in addition to improving the car's aesthetic appeal, would make it a highly desirable proposition on the second-hand market...
Tell us about your car in our Driver Power survey.
For more breaking car news and reviews, subscribe to Auto Express magazine. We'll give you 6 issues for £1 and a free gift!