I'm considering a nearly new, top spec Nissan Qashqai and I'm unsure whether to opt for a petrol or diesel model. The car will be mostly used for commuting. My journey is 20 miles from home to office, half to two-thirds of the journey is 60-70mph roads. The rest is motorway stop-start congestion and typical rush hour town traffic. The car will also be used occasionally for long journeys to visit family (150+ miles). My annual mileage is unlikely to be more than 12,000 per year and I intend to keep the car for the long haul. On the diesel model, is the DPF technology similar to other manufacturers and potentially a cause for concern later in the car's life? Are there any alternatives to the Qashqai (in a similar price range) I should consider?