ACCORDING to Prime Minister John Howard, our population is diminishing. The natural fertility rate – the number of children a woman has in her lifetime - is said to be 1.8, down significantly from the 1960s when it was 3.5. Such dire warnings should make the case for a seven-seater SUV an exercise in excess, right? Not according to Audi, which has just launched its new Q7 quattro, with five standard seats or the option of six or a third row of seven seats. Already 70 per cent of buyers have opted for the seven-seater option. So is it the ideal family wagon?