We have a BMW X3 diesel, which we have had for five years. It's a 2012 model with 65,000 miles on the clock. Understandably, we have only done 3000 miles this year, mostly short trips and are quite obviously not using it enough. Are there measures we can take to prolong the time before serious problems occur? The car is pristine and we really don't want to sell until hybrids or electric cars come into our price range.