The design was influenced by three historical Alfa Romeo models: the 1900, the Giulietta and the Giulia. The 156 achieved a drag coefficient (Cd) of 0.31. Interior styling The original interior builds on a deeply scalloped upper dashboard and simple centre console. Also a MSR (Motor Schleppmoment Regelung) was added to the car, this device prevents wheel skidding by restoring torque to the engine for example when the gear is shifted down abruptly under conditions of low grip. All of the main controls and displays are angled towards the driver in typical Italian sports car style, although this can sometimes be awkward for passengers who will struggle to see the interior clock. Typically, for a smaller executive car, there is ample room up front for the driver and passenger to sit comfortably, with very comfortable seats. The Crosswagon was made to look more like all-terrain vehicle by unique front and rear bumpers and door sills with steel inserts. The GTA variants shared a common interior with post-facelift 156 variants.
Passive safety was also made better, all versions got window airbags as standard. After the introduction of the 159 in 2005 the Crosswagon remained in production, and in 2007 it was the last 156 to be discontinued. Despite being a family car, the interior design lacks cup holders, which normally come standard in saloons. The steering was also made faster, only 1.7 turns from lock to lock compared to 2.1 in normal models. The very first GTA was sold via on-line auction, from September 13 to 23, the duration of the Frankfurt Motor Show.
The doors, bootlid and bonnet were also shared. Other than the ride height, special 5-spoke 17 inch wheels and a «Q4» badge on the tail set the Sportwagon Q4 apart from the front-wheel drive 156 versions. They were rated at 140/150 PS (103/110 kW) for straight-4 1.9 litre 16-valve and 175 PS (129 kW) for straight-5 2.4 litre 20-valve. Also electronic stability control VDC (Vehicle Dynamic Control) with an emergency brake assist device and slip control ASR (Anti Slip Regulation) came as standard.