Looks like it, and if so - it's definitely not an O ring you need to buy. That's a rubber washer of sorts.Number5 said:Is this not it ?? Shaft Seal Kit ...
https://www.ebay.co.uk/itm/BMW-Z4-E85-Cabriolet-Convertible-Roof-Pump-Motor-BOLT-DISC-MOTOR-SHAFT-SEAL-KIT/283448104605?hash=item41fed2d69d:g:4qQAAOSw-4BXaWKy