If it's just the one kid, then I see no reason why I couldn't continue with the AE102 - it has a big boot for it's size, the back seat is reasonably roomy and access is decent. Two baby seats would be a problem, but once they grow up then two boosters wouldn't be an issue at all.
Hell, when I was a kid our "family" car was a brand new 1984 KB Laser, and that was an upgrade from a 2-speed KE10 Corolla (me, being the second baby, was the cause of the upgrade/upsize). That took 2 parents and two kids in childs seats/boosters + stuff in the boot to a lot of places, but got sold in '96 and replaced with a Camry, mainly for extra touring ability (SXV10 Camry has close to _the_ biggest boot I have ever seen outside of a station-wagon)