CAN bus basics, MISRA standards, use of volatile, const, meanings of the static keyword, why malloc is a really bad idea in small embedded things, safety integrity levels.
Meaning of 'realtime' and some considerations surrounding it.
Matlab and Simulink may be areas of enquiry, together with automated code generation using these tools.
Basically, lots of mostly low level embedded stuff, plus some car stuff and some use of automatic code generation bits and a few safety bits.
there is usually little point in interview prep in this sort of sense, any engineer worth their salt can tell very quickly if you claim experience in something but have only read the Wikipedia entry.
Far better to spend the time coming up with good answers to the 'soft' questions, you know the ever hated "Tell me about a time you had a disagreement with a college..." stuff, this is actually worth thinking about in advance so you have some good answers, the technical stuff just has far too many directions it could go in.
Regards, Dan.