Could you please advise which is the most fuel efficient 4-wheel drive model of the Tiguan range? I currently drive a Volkswagen Driver and I need a vehicle which has a lot of space for my grandsons and family pets. I intend to keep the vehicle long term, therefore I am looking for the most fuel efficient model and one that won't be too heavy to handle. However, the model I drive at the moment doesn't have powered steering. Are there any extras I would be wise to include? Is buying online a safe option?