Blake442 said:
Just to expand on this a little bit, GM has used alphanumeric option codes since at least the 1960s. These are the codes on your SPID, for example, or on the build sheet for older cars. Most of the time the first letter stands for a particular type of option. 'A's, for example are mainly interior options (power seats, power mirrors, etc). 'C's tend to be comfort options (C60=A/C, etc). 'F's are suspension related (FE2, F41, etc). 'J's are brakes, 'L's are engines, 'M's are transmissions, 'U's are electronics (radios, gauges, etc).
The 'W's were used by Olds for special performance equipment. Chevy used the 'Z's for this.
