i think they all make some sort of noise with fierd angles in car parks and on full lock etc, i wouldnt worry unless it does it all the time.
Theres a multi storey carpark in brum that makes a really wierd noise on my tyres, i thought they were flat or something as they squeal like hell and feel really wierd through the steering wheel!
I got out a couple of times as I thought there was something seriously wrong, even felt like something from underneath the car was dragging on the floor.
It was just the type of surface of the carpark though!