I bet there is something to do with the temperature and the moisture on the road. Maybe some oil or some kind of dirt.
And the moisture might turn the oil on the road surface into a film of oil (the most dangerous)
Sniady, what brand and model of tires do you have on your GTV?
I almost killed (well... hurt) myself on my bike one night heading home from school. It was cold, it was moist (with fog), and I was tired.
I was going pretty slow (about 40) and leaning for a turn, all in a sudden the rear tire let loose and then the front tire. Almost got high-sided when I tried to recover it. After that, no more cold tires leaning for me.
I always warm my tire up before I do anything now.
It's kinda fun to power slide when the tires are cold though
My dad told me that can help to warm up the tires too!!