I thought Android did rSAP too.. The only saving grace of rSAP is a better quality signal in marginal areas (like the bloody M8!!) as it uses the car's antenna instead of the phones.

rSAP is more a function of the particular phone than Android or not Android - and usually down to which manufacturer makes the phone. Just check out the phone spec on the manufacturer details.

Remote SIM access profile Bluetooth adaptor cradle.
An enhancement of the factory-fitted option "Mobile phone preparation - Low". It enables mobile phone handsets to connect to the phone preparation via Bluetooth Remote SIM Access Profile (rSAP). When handsets are connected, the cradle enables the use of the external GSM car antenna and deactivates the handset antenna in order to minimise GSM radiation in the car and handset battery consumption. The handset is put into standby mode so battery power drain is minimal. Once connected, the cradle connects to the handset automatically and details of up to four handsets can be saved. Only handsets with Bluetooth rSAP functionality are compatible with this adaptor.