Hi,
The S12XE does not have FlexRay module integrated on chip, niether do S12XD. The only chip with that feature is S12XF family (F indicates FlexRay). However, the MFR4310 is the FlexRay communication controller and can be used with S12XE microcontroller.
The EVB9S12XDP512 evaluation board has dedicated part and headers to plug-in the MFR4310FRDC daughter card:
FlexRay™ Daughter Card (FRDC) (MFR4300FRDC)
From the EVB schematic you can see where flexray header pins are routed (to which MCU pins), so you can use the same implementation with S12XE evaluation board which does not have that headers on it.
Hope the information helps.
Regards,
iggi