Is 99420 miles a lot?

I would be getting a comp test done, if they are all with in specs you should not have a problem, check the service history in the service book, a well maintained diesel will go for years and years, 500,000 Kms is not uncommon befor any serious work should be expected.Service costs are not that bad, a fraction more than petrol ideally fuel and air filters changed more often then petrol.

Thanks will try and get the test done. :)

make sure you get the engine and trans up to operating temp. see how they do, by then you should have an idea then try to scan the sytems and subsystems for faults. most likely if anything is wrong it will show up then. 6miles/10 km is a drive cycle, some faults take 2 or 3 drive cycles to show up. try driving 20 minutes then shut the car off for a few minutes then do that a few more times. these cars do self tests while you drive.if you get the car make sure to keep up the maintenance as mentioned above. check the owner's manual foor maint. schedule.