I've also avoided getting petrol when with DS - but on the occasions I've had to, I leave him in the car while I pay - it has never taken more than 2 minutes to pay and it completely stresses me out - but I can see the car from the counter. That being said, I was talking about this with another new mother and she told me that someone told her it was illegal to leave your child unattended in a car at a petrol station. Sounds really weird to me, as technically isn't it illegal to leave your child in a car unattended full stop (not that the legality of it all is why we don't!).