We had the is same issue when I was expecting Lexie.

So I investigated all the options, and realised that pretty much the only suitable car with enough space was a Commodore station wagon........it fits our 2 Maxi Riders and a capsule (soon to be switched to the third and final Maxi Rider...).

The boot of course fits all teh other stuff you need.......

I had to trade in my sexy black Mazda for the Mummy Wagon. Sad but true. But, it fits us all in.......

My SIL had the same issue: she had a Rav4, but it won't fit 3 car seats, so she has temporarily swapped with her DH to use his Commodore whilst her 3 littlies are in capsules/seats.........