Was doing an interior detail on my Monte yesterday and I found some scratches on the plastic screen over the speedo and rev counter. Really annoyed as I must have done it, possibly accidentally wiped it with a dirty microfibre cloth or something     ! I can only see some of them at certain angles, but typically I can see some at the angle I look at when driving! What can I use to remove them?

Something like Meguiar's PlastX used very sparingly on a microfibre or pad should help. Go gently, and keep checking.