Hi,
My Jazz has been serviced on schedual (give or take a few miles!) and is still running with the same exhaust. The mileage has been 50% motorway 30% A raods and the rest town driving. The only two problems I have were an ABS sensor malfunction (poss caused by having brakes done on the cheap by neighbour) and now I need to replace the EGR valve. I'm not sure what you guys use but I have got Michelin energy tyres all round the last ones I replaced had covered 44,000 miles which seems very reasonable! Thanks to a hit and run taxi it now has a large dent in then rear bumper !!