Alternatively this can be purchased on eBay:
Plug-in easily fits into the 20-pin diagnostic connector to allow flashing of the ECU through the OBD2 port in car. This bridges pins 14 to 18 (write mode enable) and 2 to 17 (obd plug enable) which is a requirement before flashing an MS41 ECU.
Compatible with MS41 / MS41.1 / MS41.2
MSP E36 MS41 PnP Write-Access ECU Programming Plug-in (OBD2 only)
Purchase and support are dealt with on the MSP website.