Hi, Julie.

As the folded stroller is 100 cm (1 meter) long, I think it will be a real struggle to put it in the Mini Cooper boot. It might be possible with the seats folded or after (quite annoying) removal of the wheels, but it won't be comfy. I would not go for an umbrella type of a stroller with a Mini Cooper, rather think of an ultracompact, e.g. the Miley2.