well, i went through Saturn BISO CD boot sequence with disassembler
not all the way up until AIP launch, but i'm almost there
and it doesn't look like it cares at all about those keywords
not about 'Maker ID' nor 'Product Number'
it does check however 'Hardware Identifier', 'IP Size', 'Security Code',
'Compatible area symbols' and 'Area Code Group'

so i'd guess it's probably in CD unit itself
somewhere near protection - warm and cozy

but i'm not to trust on this
if somebody is interested in subject - it's better to check for yourself