get the dimensions of the e89 seat and the dimensions of the e85 seat (sport and SE).
you may find that it will phsyically fit but you will definitely need a custom rail made... shouldnt be too expensive, I imagine Machinemonkey could whip you something up.
you'll probably need seat occupancy sensor from ur current passenger seat to be put into the e89 seat (someone should advise as I dont know fully)
I am unsure if the heated module in the seats would work with an e85 heated seat panel , plus you will need the wiring loom for the heated seats to operate.
if you're interested in the e89 seats then I'd say get the sport ones with electric non heated to save alot of hassle.