2012 BMW 1 Series Spied Testing, Three-Door And Cabrio Rendered

Images of an all-new 1 Series in five-door hatch form captured earlier this year revealed that production of the next-generation 2012 1 Series is well underway, and new spy photos this week show that its three-door compatriot is also in advanced development.

Our earlier three-door and five-door hatch renderings (below and in gallery) offer a look at what is expected to lie beneath BMW's trademark swirl camouflage.

While that camouflage makes discerning the new 1's design details a little difficult, it is clear the sharp character line that runs along the current car's flanks will remain a feature of the new model.

It also clear that BMW is aiming for a 'shooting brake' inspired roofline for the new 1 Series three-door, setting it apart from its five-door sibling and giving it a sportier look (suggesting the next-generation 1 M could appear in both coupe and hatch form).

As for the nose and tail-lights, BMW is keeping those a closely-guarded secret, opting to cover up the prototype's entire front and rear ends.

Judging by the straight-edged rocker panels, the 'sagging' lower crease of the current model may be dispensed with.

A cabriolet version of the new 1 Series is also rumoured to be in the works, and while this variant may not arrive until early 2012, our preview rendering (below) offers a look at what we might be able to expect.

Recent images revealed dual tailpipes protruding from the rear bumper of the five-door, a layout usually reserved for BMW's twin-turbo models. It is possible that this particular prototype will enter as the 135is, utilising the same twin-turbo N54 3.0 litre six featured in the new Z4 sDrive35is.

The 'regular' 2012 BMW 135i is set to switch from its existing N54 twin-turbo setup to the German carmaker's new N55 single-turbo inline-six.

While the new 1 Series had been expected to arrive next year, the announcement of the 2011 BMW 1 Series M earlier this month suggests the current generation 1 has at least another year in it, with the 1 Series M likely to overlap into the next-generation 1's production cycle.