Sensible centres label them as Parents with Infants spaces - I use them whenever I can get them and always use a carrier. They are closest to the centre entrances and it is safer with small children not having to traverse the carpark, and are usually wider spaces which makes getting infants in and out of car seats easier (which is impossible sometimes the way some idiots in 4WDs park).
I've never had anyone whinge about it, and if they did I would just point out that I have a pram in my boot and ask if they would like me to get it out just to satisfy their sense of self-righteousness.

