Have only recently got X-Plane 10 (just before 10.30) I am wondering if this is how rain does look normally or is something going wrong? Once I reduced speed to land it seemed fine but at full speed it just looked so wrong. The rain was moving but was in squares around all the windows, hope this is a bug as it completely ruined the flight for me.

 

Rain on the windshield is different depending on the aircraft addons you're using, i.e. each addon developer has to implement it individually.

The particular issue on your screenshot is a bug in the A320neo. I observed this issue, too, a while ago, when I was still flying it. I can't remember the reason, though. Maybe check if you're using the latest version of the A320neo.

Ahhh ok so its the a320neo causing it. I have the latest version that runs on 10.30 only.