I've got enough subscriptions in my life. 50 euros a month would be 6000 euros after 10 years (figure a couple years more than the 8-year warranty in the US) that could be put towards a refurbished battery if the car needed one at that point. The reality is, on a 10-year-old car, a little range degradation isn't a huge deal, especially if that car is being driven around town and can be charged nightly. I'd rather own the things I buy, and not pay to be tied into yet another monthly bill.