The BMW has already had a battery charger under warranty - just as well, as it would have been £3K if it had been out of warranty. I don't get to talk to the owner much, but he did say he didn't intend to keep it for more than a couple of years (planning to return to Poland for family reasons).
The Auris owner has had it from a year old & it has now covered around 170,000 miles. At 7 years old it is now into the 15 year extended battery warranty - the standard warranty is 5 years, but having the vehicle regularly serviced by Toyota extends the battery warranty in annual increments up to 15 years. A genuine Toyota replacement hybrid battery for the Auris is just over £1200.
The only parts changed other than service items (Tyres, brake pads - still on original discs) have been the exhaust heat shield & the front brake stone guards. It returns 55mpg in winter & 60mpg summer - around 2-3mpg better than my Hyundai i30 1.6 turbo diesel with DCT, though mine is an estate & Andy's Auris is a saloon.
Andy has a similar 50 mile each way commute to me, though his route is less congested than mine, so steady speed dual carriageway driving with few starts and short journeys for both of us. He is pleased with car & has no plans to change it any time soon, though when he does decide to do so he is inclined to get another Toyota hybrid to replace it.