Although you question has to do with automobiles, today's automobiles are filled with electronic gadgetry that likely requires programming on the part of manufacturers after it is installed. There is something called AVR fuses that might be of interest to you. They appear in a large variety of contexts on the internet -- mostly electronic. The words lfuse (low), hfuse (high), efuse (extended) apply to the number of bits available to encode the fuses for proper implementation and operation.

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Note added at 15 hrs (2006-12-25 00:36:10 GMT)
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Willmatter's link:
http://www.atmel.com/journal/documents/issue4/pg46_48_CodePa...