My little one was born about two years ago and I've just about managed so far...
For the first baby seat I got a Maxicosi CabrioFix with an EasyFix base. This is just about the only rear facing baby seat that will fit in the back seat (I couldn't find out how to turn off the air bag - mines a 98 GTV). The passenger seat will have to be pushed all the way forward and be totally upright. This is a right pain in the ar$e for the passenger - well pain in the back in a better phrase. Only good for journeys of less than a couple of hours. The down post of the base will also leave a dent in the rear fabric of the front seat and the base will leave almost permanent indentations in the rear seats if you leave it in place. It's a real pain to take in and out so mine stayed in there.
Now we have a Priori XP in the back. The passenger seat has to be almost all the way forward but can recline to a comfortable angle at least.
Take note that neither of these seats is recommended for this car. Indeed they don't recommend any child seat in the back of a GTV! So if you have a smash and there's legal nastiness as wall a physical I don't know where you'd stand.
Both seats are a pain to get in and out and involve a fair bit of contortion to get a child in and out. You have to watch for 'Buckle crunch' ie where the buckle sits on an angle at the top of the seat - the GTV has a long strap and they will stretch if you leave the seat in place so best to unclip it when your not using it. You'll also get loads of little feet marks on the back of the seat once you've got a toddle seat in so its shoes off in the back!
Be very careful about your choice of buggy too. Our Maclaren Techno XT fits in the boot but it's a squeeze and you have to pack it in the boot last. Most other buggies won't fit at all.
I'm not sure how much longer I'll last with the GTV, don't want to sell it just yet but am looking at a GT or even a Coupe.
98 GTV 2.0TS.