Hi,
Just wanted to share some information which I hope might be helpful to those looking for a pushchair/travel system to fit in a ridiculously, infuriatingly small boot . I have a C1 with a boot size of 100cm x 40cm x 30cm, and DH and I have been actually laughed at by both shop assistants and random members of the public alike as we went to several shops and attempted to fit various pram systems into the boot.
I was looking for something that would fit entirely in the boot of the car, fold all in one piece (didn't want to have a seat unit sliding round on back seat), be suitable from birth and could be combined with a car seat to form a travel system. However, DH has an estate (company car), so we did have the option of getting something a bit more substantial (with more features, such as carrycot) for weekends and holiday use. After a lot of research, we have actually ended up purchasing two travel systems, one for each car...but both for under £500, including car seats.
I have got the Joie Aire + pushchair/stroller which fits entirely in the boot of a C1 when folded up. When used with the Joie Gemm car seat, it can be used as a travel system. The pram alone is suitable from birth as it fully reclines, comes with footmuff and raincover, etc...only thing it doesn't do is face the parent. You can buy the pushchair on its own for £60, or pushchair + car seat from £100.
We have also purchased the Joie Chrome travel system (front/rear facing, folds both ways, raincover, footmuff, suitable from birth, etc) for when we're using DH's car. It's on offer at Mothercare at the moment so for £230 you get the frame, seat, carrycot and the Joie Gemm seat. This means we can use the same car seat on both pushchairs.
We are also going to purchase the Joie i-Anchor isofix base (£100), and the i-Anchor seat (£160). This car seat is suitable from birth, but can't be clipped in to either of the pushchairs as it's so much bigger. However, it means we have an extended rear-facing car seat to use up to the age of 4 and if we have another baby before this one is 4 we can re-use the Gemm car seat for a while.
I wanted to share this long and rambling post in case I am able to help anyone else in this situation. Hopefully it can help someone else out, and prevent them having the same "ohmigod we need to buy a new car" panic that DH and I experienced.