BMW is set to unveil its new xActivity fwd concept vehicle at the Detroit Motor Show on 5 January. The sports activity vehicle - which will be denoted X3 - combines X5 looks but with a unique frame-structure convertible roof.

##BMWsav--right--The BMW xActivity concept car##

Reinforced longtitudinal rails connect the A-pillars to the rear of the car on both sides, removing the need for B- or C-pillars. This gives the carmaker the freedom to make the most of a sporty look.

The xActivity will enjoy BMW's 231bhp 3-litre straight six, with power delivered from very low engine speeds to enhance the performance on gradients. It also features a brand-new driver control system that offers traction control delivered individually to each wheel.

Internally, the innovations will include “smart” seating materials. The seat comprises pressure-sensitive materials that allow for adjustment solely through applying pressure to the seat components.