Combines squishy, and whirly to describe a lack of control or a vaguely spinning motion. Often used to describe 'out of control' and unpredictable motion. Thus can be applied to the feeling of being drunk, or the feeling when a motorbike doesn't feel quite right and could lose control at any time.
Pit Crew: It's starting to rain
Shumacher: The car is feeling a little squirly, I am coming in for some wets.
Pit Crew: Roger that.