I’m looking for a premium diesel SUV automatic with a budget of around £40k. I’m concerned that winters in this country are going to become increasingly more severe for the foreseeable future due to decreased sunspot activity. This, along with the very poor state of local roads, makes the purchase of this type of car very compelling. I’ve looked at the 3-litre versions of the Audi Q5, BMW X5 and Mercedes ML and was wondering what your advice would be for best long-term ownership. The car will be purchased either as an ex-demonstrator or new in six months or so.