E9x Sliding Armrest

[merlin5]

Anyone with an E9x have the sliding armrest option? Is it useful on an Auto?

[noneedtolift]

I liked it. Definately more comfy.

[Bosh 964]

I suffer from shoulder pain and cannot rest my elbow on the E91 armrest like I could on the E46 whilst holding the wheel worsening the pain. Does the sliding armrest resolve this and if so can it be retrofitted?