Only you can answer the question 'is it justified'.

You know how its been serviced and by whom, you know how its been driven and by whom.

If its been driven well and serviced properly....and i don't mean every 2 years or 20k miles between oil changes despite what is recommended in the comic...then i'd save the money.

Its a quality car and if treated well should give another 100k miles without a murmer, your use is as good as anyones.

My innate cynicism suggests to me that any fault you tried to claim on would be put down to wear & tear.

Or "consequential damage" is another favourite mentioned before around these parts.

e.g. hose splits, that's a wear and tear item. Catastrophic overheating caused by loss of coolant lunches the cylinder head, that's consequential damage from the hose failure.

Payout = 0.

The BMW warranty is actually very good - which is why it is expensive. It can also be extended indefinately - as long as the warranty has never been broken the car is still eligible for one. There are, for example, some old E39 M5's about which the warranty has been kept up on which are worth thousands more than examples which haven't.

At the end of the day it is an insurance policy and a calculated risk. You could just put the same money away for potential bills and you may well come out ahead, you might not.