When to retire a middle-aged car

[Twilkes]

2002 Honda Jazz, about 110,000 on the clock, average 9000 miles per year, runs well, has generally cost £100-£400 per year in maintenance/MOT fixes over the last 3-4 years, depending on whether anything major needs replacing.

At what point should we ditch it and get something younger? Ditch it when the service costs increase, or drive it into the ground?

This was bought in 2009 for around £4k, and would likely buy a similarly aged/priced car next time.

[Twilkes]

Thanks - although reports of our careful servicing have been greatly exaggerated, it's more like 'enforced' maintenance.

So I can get an idea of costs, if anyone has a 5-6 year old car, how much would you expect to pay in servicing/maintenance in an average year? Anyone had a few clear MOTs with no maintenance costs at all?