- 1968 Factory-verified
All. Factory kit resolves this: option-price grid code Z = "SHOULDER BELTS (Rear)" (p.147) and individual accessory-code list "Z SHOULDER BELTS, Rear (2)" (p.21); front (convertible) shoulder belts are code H, not Z. CLC 1968 accessory list agrees ("Z Rear shoulder belts"). Corrects an earlier reading of Z = *front* belts.
GM Heritage factory kit — 1968 Cadillac VVI, p.147.GM Heritage factory kit — 1968 Cadillac VVI, p.21. - 1967 Single-source
All; per CLC/Mileposts 1967, when front shoulder belts were still optional (before the mid-1968 federal standard made them standard on closed bodies, at which point Z shifted to *rear* — see the 1968 row above). No factory-kit corroboration for the 1967 letter yet
Z Factory-verified
Also described as Rear shoulder belts
Documented applications
This page aggregates every documented appearance of Z in the Cadillac reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.