Hi Nicky,

It's going to be really tricky to find a premium SUV that has seven seats but low emissions. If you're buying brand new then you do have some choices. The current BMW X5, in rear-drive 25d form, emits 154g/km, which means motor tax of €390. The new Volvo XC90 is in the same bracket for the D5 model (or in Band A1, €170 a year for the T8 plugin hybrid). If you're willing to come down a little in size, the new Land Rover Discovery Sport can be had as a seven-seater and has 149g/km CO2 emissions, so is in the same €390 bracket. There is a front-drive 2.0 Discovery Sport coming later this year though that will be in Band A4, with 129g/km and €200 tax. 

If you're buying used, or more than a couple of years old, then you're really going to struggle. Anything with a premium badge and seven seats is going to be in the €1,250 tax bracket. Maybe consider a Mercedes E-Class E 250 CDI Estate with the little flip-up seats in the boot? A much more affordable alternative and better to drive than any SUV.