Dr. Flyview is probably thinking of earlier mustang O2s being compatible with OBD1 E36 with the swapping of the connector.
taxi615.....kinda curious as to your logic. Why would a person go out and spend $400 on an O2 at trade cost when you can go and get the same one re-boxed from an aftermarket supplier for $65 trade cost??
OP If you want a good deal on sensors go to your local Partsource and as for BWD O2 sensors. You want 2 upstreams because they are half the price of the downstreams and compatible in both locations. Why waste your hard earned money when you dont need to??