ah ha!
The pricelist for the E91 lists the following:
HiFi - 10 speakers:
4 midrange (2 in front doors + 2 in parcel shelf)
4 tweeters (2 in front doors + 2 in parcel shelf)
2 bass under seats
Logic 7 - 13 speakers:
2 bass
6 midrange (2 in each door + 2 in parcel shelf)
I make that 10! Unless it's front doors only?
4 tweeters (2 in front doors + 2 in parcel shelf)
1 midrange in the centre of the instrument panel
As standard it just says "Loudspeaker system". I would surmise that it may be the HiFi setup without the bass units.