The F31 and the new Clubman are identical at 17.5 cubic ft, but BMW was way more usable. It feels like the space is less tall, but wider and deeper in the 328. I didn't measure it and I'm too lazy to look up dimensions, but a stroller fit much better in our car. In the Clubman, we could get the stroller in, but the only way to put something else in was to stack on top of it and (potentially) block the rearview mirror.
'76 911S | '14 328xi | '17 GTI | In memoriam: '08 848, '85 944
"Here, at last, is the cure for texting while driving. The millions of deaths which occur every year due to the iPhone’s ability to stream the Kim K/Ray-J video in 4G could all be avoided, every last one of them, if the government issued everyone a Seventies 911 and made sure they always left the house five minutes later than they’d wanted to. It would help if it could be made to rain as well. Full attention on the road. Guaranteed." -Jack Baruth
"Here, at last, is the cure for texting while driving. The millions of deaths which occur every year due to the iPhone’s ability to stream the Kim K/Ray-J video in 4G could all be avoided, every last one of them, if the government issued everyone a Seventies 911 and made sure they always left the house five minutes later than they’d wanted to. It would help if it could be made to rain as well. Full attention on the road. Guaranteed." -Jack Baruth