modern cars are growing and growing, but the trunk size is going down and down. even large looking SUVs have trunk sizes that are not in relation to their massive total size.
if kids are arriving yo need to carry buggies and a lot of stuff. choose a car where the trunk is wide enough that the golf bag fits directly behind the rear seats. Be careful with the driver. if the golf bag needs to lie diagonal, the trunk does not fit...
I have 2 children and an older standard Mercedes E Class station wagon, it works fine. the same in new version, no f*ckn way.