Interesting small cars, but you're paying quite a lot for the image. Don't be fooled by the entry level pricing on new cars, as the 'essential' extras quickly add to the price. This also means that the published (good) residuals aren't necessarily accurate.
The first generation BMW MINI had a lot of teething troubles, the second (current) generation has fewer, but there are a few known faults. Check out http://www.mini2.com for more info (look at the faults and fixes forums).
Having had 3 different first generation BMW MINIs, all with glaring problems (first was rejected after 6 weeks, second was a loan car I had for 4 months whilst waiting for the replacement, third was rejected after 2 months), I'm not sure I'd want to own one out of warranty...
It's always alleged that the MINI project is loss making as a whole because you're buying a lot of engineering for the money. This is good when it all works, but could be pricey once it goes wrong.