My qashqai seat recently started squeaking. The best way to recreate the noise would be to veer right and then to turn left a little abruptly.
The dealer replaced the seat base under warranty and it seems to have resolved the issue (fingers crossed)
I did find some videos on the internet which demonstrate the noise we were having.
Thought I'd post as think others might have the same problem
https://www.youtube.com/watch?v=xkW_u_QnY54
https://www.youtube.com/watch?v=sDwpAWx6Ols