For the past few months I've been getting increasing pressure from 'she who makes the rules' to go 7 seats - I won't get into the in's / out's of this debate suffice to say I've accepted it's probably inevitable. I'm currently driving a 2006 R53 Cooper S, love it and want to keep it. I also promised my kids I'd keep it for them until they are old enough to drive (only another 10 years ). She has the e90 and until yesterday my intention was to trade this in for something newer with the 7-seats. The mini is a good example (low mileage at 118k kms, factory LSD, good service history, etc) so now I'm thinking of taking the mini off the road and getting myself into a 7-seater E70 X5. Then maybe later next year get her into a new smaller car like an A3. I have a budget which I don't have to spend and I don't really care if it's 2008 or 2012 (assuming within budget). We don't do much in terms of mileage so daily running costs don't bother me but I would like to understand more the annual maintenance costs, basic servicing, etc - I've read they are hard on tyres, bushes, etc but how hard - we'd average 10km per day with the odd longer trips thrown in so I'm struggling to see how costs could be very onerous but clearly I don't know hence this post and hopefully some real feedback based on experience?

Is it a mad idea?

Thanks in advance.