mirroring multiple objects at once

is there a way to apply mirror modifies to multiple objects at once? - I know the objects can be joined, apply mirror modifier and then separated - just that I want to avoid that since the unwanted materials needs to be deleted after the objects are separated.

Add the modifier to one object. Select all the objects you want to have the modifier, ensuring the last object selected is the one with the modifier you want to copy. Use Ctl+C / select Modifiers / select the modifier you want to copy (mirror)

You can use Ctrl+C to copy a whole range of parameters.

Richard - thanks a lot!
That is exactly what I was looking for.
Thanks again.