[GT-E]

I have the ISOFix as standard on my new Jeep, but I cannot find any local seats that support them. Everything is out of the UK or USA that makes the shipping difficult. We have decided to stick with the old type, as it is way to costly to change.
As for your questions, I do not know if you want the Audi retrofitted or the seats you have. AFAIK you cannot do either. The baby seats need to be designed for the ISOFix and the mounting points are right down near your hips. I guess you could attach them to the belt buckle, but it would not be right. I think you will need to just do what I have done and live with the old system. One day the government will realise that road safety is more than just fining drivers for speeding