My wife and I do 400 motorway miles every weekend and carry a lot of kit. An estate is essential. We have a Mercedes E240 2005 petrol model estate at present which has done 95,000 miles and which has always been promptly Mercedes serviced. It has so far been faultless but I'm getting worried about reliability at that mileage. So my first question is whether I should be nervous? And if I want to be sure, what could I ask Mercedes to check out or renew to be certain of another 30,000 miles? Cost, compared with renewal, is not a problem, within reason. But if you think I'm pushing it and should consider a replacement what would you advise? It seems to me to be a toss up between a big Audi Q model, an E Class replacement, a Volvo or a Lexus hybrid. Criteria are safety, motorway silence and comfort, reasonable economy (because we get 29.4 to the gallon from the present car and I don't want to drop much below that), size because we carry big things, and finally what I might describe as driving aids. My wife who has the car during the week is a nervous driver and needs all the help she can get. I do all the motorway stuff so for different reasons the same applies to me. Cost is not a factor between say £30,000 and £40,000. What do you suggest please?