Is the stock BMW sensor a standard potentiometer? Is so, can you use a hall effect sensor? Non-contact sensors should last for a very long time.
For my TPS, I sourced the Variohm sensor from Digikey—it features a standard D connector and fit my BMW throttle motor. It's also dual sensing which is needed for DBW.
https://www.variohm.com/products/motorsports-sensors/rotary-position-sensors-for-motorsport/euro-xpd-d-shaft
https://www.digikey.com/en/products/detail/variohm/EURO-XPD-2832-812-214-911-00/22286984