Rubbing/grinding noise when turning my 2000 BMW Z3 to the right

What could cause this noise?

Any number of reasons.

One could be from sliding into a curb and damaging a steering component or other suspension parts.

The beginnings of worn wheel bearings or even tire separation.

Look at the inside tire sidewall for rub marks.

Look up under the front fenders (both of them) to see if some of the plastic fender liner has come loose and is rubbing against the tire when you turn to the right.