Our main concern was the car issue too, I think with a bit of shuffling and careful research you can still fit 3 car seats into the back of a normal car.
We've got a Ford Focus, and at first glance you'd think there'd be no way of getting 3 car seats in, but apparently it can be done so there is hope for us yet!
Our main dilemma though is that we live in a 2 bedroom house! It's got potential for a loft conversion but it's no where near in our financial reach right now 
I did look into evening work, but DHs work load can often mean he isn't home before 6pm, which means I couldn't start work before 6.30pm at the earliest, then you'd have to take into account traveling costs for me to drive to and from work, and then us to take a cut in Tax Credits due to my new income blah blah blah, in the long run, it really wouldn't be worth it.
Sad that a system shows we are better off if I don't work 
I do most of my shopping on eBay, some great bargains to be found, also car boot sales are fantastic for baby equipment. For DD2 we found a lovely, big, old fashioned wicker moses basket for £1! 
Our motto is as long as we can pay the mortgage and bills, we can just wing the rest 