Come October, my office will be within the extended ULEZ in London. The Z4 will be the only car we have that is compliant and it is not really a long distance commuter car. My round trip is 450-500 miles 90 % motorway every 2-3 weeks. In addition I don't want to put such heavy mileage on the Z. So, I have been looking at alternatives, and wondered if anyone has real world experience of the Mercedes diesel C300h estate. I'm attracted by the alleged very good economy of 60-70mpg and the low tax. Older Mercs used to bullet proof, but I wonder if they still are? I need a good motorway cruiser that is reasonably economic and which can double as occasional race support and tow car. Not much to ask I know. Any other ideas..... ? Thanks.