The 8s were a whole different audience than the 5 series.
It seems more targeted at the 7 series owners that wanted a Sporty luxury cruiser.
I sincerely hope that it didn't share any panels with other BMWs but it does share most of the driveline. Otherwise I think Unique is a good description. $pendy works too.
Anyone would play Hell prying most of us out of our 8s to put us into something Practical like a four door.