This can be said of 99% of new cars the op is looking at two high milers with really unknown history I also think the diesel problems are out of all proportion compared with the number on the roads.

I have now covered 10,000 miles in my 6 and have nothing but praise for the car. It is a comfortable car to be in for long periods,is quiet at legal motorway speeds(and above,but whisper it not!). Fuel consumption is reasonable at between 35 and 37 MPG.just knocking about locally.On a long run it climbs to over 40. The boot is huge,with spaces for small items such as torches etc. Unfortunately,Mazda have neglected to fit a spare wheel,electing instead to provide a stupid container of goo. Build quality is very good,and probably on a par with anything in this class for the price. A word or two to the OP: if you do get one,avoid the diesel at all costs (too many horror stories). My experience with the Mazda agent (RRG in Stockport) have been nothing short of excellent.

I concur - I put 30k-odd miles on mine (bought at 73k) but since it's a 2005 I have a spare wheel! Trying to sell it as I'm driving a different sort of Mazda, and although there's only me to transport about now, I did appreciate the vastness of the boot and the decent seats when I bought it as we were doing up a house.