I can definitely give the Touran a recommendation. All 5 of its rear seats feature isofix if you only use 5 the boot is really big as well. Also had a C4 Picasso which fit 3 child seats across the back. The best are the MPV style with 3 individual seats instead of the traditional bench.
Current Car
KIA Sportage GT Line Mhev
Previous Cars
Peugeot 5008 Allure Premium
VW Touran SEL
Citreon C4 Picasso