Scratchy Fabric Upholstery

What can be done to make it less noticeable ?

Seat covers?

I’ve been considering it but the seats have airbags. There is a warning not to use seat covers because of them.

It is possible to purchase seat covers that have a provision for the deployment of side airbags. You just have to look carefully to find this type of cover.

Is there a product which could be applied to the upholstery ?

Maybe. Ask at an upholstery shop where they do couches and such.