Been doing some searching. It looks like Active Backrest was only an option on the M cars. It that correct?

 

In my 08/09 brochure (Canada) seat options or standard are: "Active seat ventilation for drivers and front passenger" and "Comfort seats for driver and front passenger" which includes a two-part seat-back with electric adjustments, lumbar support and side bolsters. There are also optional "Sport seats for driver and front passenger"
If you are referring to other types of seats then the answer would be Yes, they are only on M cars.

 

Thanks for taking a moment to let me know.

 

Yes, the Active Side Bolsters are only on the M5 and even then they are optional. Not all m5's have this. That said, I don't understand why they all don't have it, even if it's not a standard feature, if you're spending $100k on a car you want to skimp on options? Luckily, I haven't seen one that wasn't loaded, but I know they exist.

 

I did a quick look and first impressions are that a retrofit may not be too crazy. My current seats are the sport seats on an LCI that have the manual side bolsters. A look on realoem shows a different motor (not sure why it would take a different motor - perhaps something more responsive/faster?) Maybe the motors, a controller module of some sort, and the buttons. It would be OK to skip the buttons and use only the idrive settings if that would be possible.

Can you fix my typo in the title?

 

I would think it would take a MINIMUM a new motor, before attempting you should try to take a ride in a car with them. They are amazing, and the response is immediate and differs depending on the turn. It will start gentle and increase as the turn becomes more severe. They really work well at keeping you planted as you take the car through the twisties. So I suspect, new seats plus whatever wiring is needed and probably a module to control it (if the module is not part of the seats already) - if you can do it you're amazing, please post a DIY if you can.

 

Unless I am missreading, according to realoem, the motors are the same.


From looking at the M5 parts
*****************************************
For vehicles with
M multifunction seat
S4MAA=Yes
13 Width adjustment, active, left 1 52107919697 $135.69
13 Width adjustment, active, right 1 52107919698 $135.69
************************************************** **********************


For the E60
************************************************** **********************
For vehicles with
Comfort seat with memory
S456A=Yes
13 Width adjustment, active, left 1 52107919697 $135.69
13 Width adjustment, active, right 1 52107919698 $135.69


And this is the backrest frame for the E60 that says it works for Active Backrest

For vehicles with
Active backrest width adjustment
or
Comfort seat with memory
Crash-active
S4MFA=Yes

S456A=Yes
01 Backrest frame, comfort seat 2 09/2007 52109154995 $1,109
************************************************** ********************************

The Active Backrest Width Controller is only $151 PN: 61356938911



It seems much too "simple" at this point but it appears the only thing missing is the controller. From the wire diagram, it seems all the motion sensors are built into the controller so no fancy integration into other car modules other than the usual CAN connections and switches.