A way to find out if your car complies to OBD would be to request (Service 0x00, PID 0x1C).
This will get you a response frame in which the first payload byte is a code that describes
what "flavor" of OBD the car actually complies to.
Possible responses are (hexadecimal, as stated by SAE-J1979):
0x01 - OBDII (California CARB)
0x02 - OBD (Federal EPA)
0x03 - OBD and OBDII
0x04 - OBDI
0x05 - Not OBD compliant!
0x06 - EOBD
0x07 - EOBD and OBDII
0x08 - EOBD and OBD
0x09 - EOBD, OBD, and OBDII
0x0A - JOBD
0x0B - JOBD and OBDII
0x0C - JOBD and EOBD
0x0D - JOBD, EOBD, and OBDII
0x0E to 0XFF - reserved.