Glad you have your Mini back! You'd think they would have been more communicative though. I had to drive a Chrysler 200 one day when my dealer didn't have any loaners available. Dealer paid for it which was nice...
My FR-S went down with fuel pump issues (surprise, surprise), and they loaned me a Prius. I decided to see if that Prius got as good of gas mileage as everyone says they do. I went through the exact same amount of fuel in that rat trap as I do in my FR-S, in the same amount of miles. And I wasn't even driving it hard!