I do an average of 50k a year (40k in the UK) and 10k overseas in hire cars
In the UK I do a lot of work in Central London so use my 500c Twinair for that as it is Congestion Charge Free, saves £12 a day driving into Central London
Twinair is 3 years old this month and done 55k in total.
Used to use a Diesel Focus for the long outside London trips, but it was sapping my will to live. So have changed that for the 500c Abarth, and will be using that for the out of London stuff, estimate to be putting 20-25k a year on it.
Yes it will cost a lot more in fuel than the Focus but at least I won't want to slit my wrists each time I get in it...