BMW’s next-generation Z4 will be a more dynamic sports car than previous iterations of the two-seat roadster, according to well placed company insiders.

BMW is aiming to make the next Z4, which is due in 2015, more agile, athletic and sportier to drive, although the character shift will be relatively modest in order to avoid alienating the sports car’s current clientele.

The styling of the next Z4 will reflect this change, with a shorter bonnet replacing the current model’s long bonnet, which can inhibit fast driving. The change will be relatively modest, however, because the current model’s distinctive long-bonnet look is popular with US buyers.

Whether there will be an M version of the next Z4 is as yet undecided. BMW has concluded that the business case for an M version of the current car is too weak to justify such a model. However, the handling balance of the next-generation Z4 will benefit from the downsized, four-cylinder N20 engines recently introduced in the current model, as the lighter power unit yields a more favourable weight distribution.

BMW’s designers must also accommodate the company’s policy of creating cars that look good over a 15-year period. The current thinking is that the longevity of modern cars means that older BMWs still have an impact on the brand’s image, so they’re now designed with timelessness in mind and avoid stand-out features that might risk ageing quickly.

The first model created under this philosophy was the current 5-series, followed by the 6-series and 3-series.