Hi. A question. I have a 58 diesel Tekna. The 105 bhp engine with the DPF. In the car today, joined my local motorway and noticed grey smoke in the rear view mirror from the back of the car for about 10 seconds which then cleared. I have had the car for about 3 months now and have done plenty of motorway driving but have never seen this before. Anybody any thoughts on what it might have been? I know that some diesels can be smoky but i have never noticed this with mine before today and i thought that the Nissan diesel was quite a clean engine, particularly with the DPF. Of course now my paranoid brain is hearing all sorts of noises from the engine and i'm convinced it sounds noisier than before!