Are you wanting another convertible? We have just bought a new car (April 2014) and have another one on order which we should get on 1st Sept 2014. We had a big Nissan NV200 which was a grata practical vehicle, nice and high, sliding back doors to easily get little ones in and out of car seats in tight spaces, loads of floor-ceiling boot space (even when using all 7 seats), reverse camera as standard, all 7 seats are full size seats (in fact the rear most 2 seats in the boot are the same size as driver seat!), last 2 seats fold down then up so they're stored away above the wheel arches. All in all it was a very big/roomy vehicle with bags of space everywhere yet it was no bigger than a standard estate vehicle. The driving position was great too as it was nice and high up. The downsides were that it was a very 'practical' car without great luxuries. The only big feature really was the standard reverse camera - a must with a big vehicle! I also loved the 60/40 split opening rear doors. Much easier to load vehicle than having a boot door that lifts upwards like cars do.
We have just got rid of the NV200 and got an Astra Sports Tourer. It is lovely to drive with a great boot size, however it is very thirsty in an automatic. Vauxhall quote 39.4mpg so I realistically expected about 32mpg but we're only achieving 16mpg!! I'm a pretty standard driver. I'm not a racer who over revs the engine, but I'm far from a Sunday driver who annoys everyone by driving ridiculously slowly
Because of the thirsty engine of the Astra we've decided to get a second vehicle (order before we knew we were expecting another baby!). We have a Mini Countryman 2.0 sports diesel automatic on order and cannot wait to get it. It is extremely fast with it's 2 litre engine but also economical as it's diesel. I must admit that I'm very worried about boot space now we have another baby on the way and doubt very much that my big silver cross coach pram will fit 
So we may need to use the Astra whenever we go out with baby but use the Mini mostly for things like the school run or shopping when baby won't need a pram as s/he can go straight into a shopping trolley.
We did also look at the Renault Clio but weren't impressed with what we'd heard about safety and the VW Golf but we wanted a bit more 'luxury' after the NV200! Lol The VW Golf does have fantastic safety records and a great size boot. You're best bet is to go found a few showrooms with your pram/buggy and try them out.
Oh just thought. What about a Nissan Qashqai or Juke? Both have new models out or coming out shortly and therefore the older models should be a little more economical.
Hope I've been of some help probably not much but it really is very much how long is a piece of string. You may hate the Mini Countryman (chunky 5 door mini) for example whereas I love it 