I take it that it is a manual as I recall reading that it is not available in an auto.

In a manual transmission, reverse is not operated via synchromesh. There is a gear that physically moves across to engage, so if the internals are just turning over, you will get a crunch as there can be enough drag on the clutch to cause the lay shaft in the gearbox to rotate.

The best way to overcome this is to first put the transmission into 1st, then without letting the clutch up to them move it into reverse. By moving the transmission into first, you effectively stop everything in the gearbox from rotating momentarily so that when you now move into reverse, the gearbox is stationary. The reverse gear that is moved across has a much greater bevel lead in to allow teeth that are not perfectly aligned to engage.