1992 Saab 900 turbo 5spd for sale

For sale 1992 Saab 900 5spd car is all stock original low Milage 78k convertible power top in excellent condition opens and closes automatically. Car was driving perfect til a clack sound now car starts but won't move forward nor backwards. I was told by mechanic it's the differential. Perfect for someone looking for a classic car at a affordable price. Who is mechanically inclined or parts. As is No refunds No returns please ask any ?