Hi guys, I have a 04/04 is 200 which only does 4000 a year, I changed the oil in november when i bought it and oput fully synthetic in it proper castrol stuff. I chjecked the oil the other day and it has gone dirty, I was thinking of changing it agian but the mechanic at work reckpns that the oil we put in will easy last a year as I dont do any miles what do you guys think????

You should change the oil with with a new oil filter every 10,000 miles/12 months, whichever comes first.