Which kits were shown in a catalog or another publication and/or were announced but never actually hit store shelves?
Paul Gill mentioned the 1/16 MPC Chevy "Apache" Stepside 4x4 kit shown in the '76(?) MPC catalog:
And MPC's 1/20 scale '56 Ford Pickup from the '78 catalog:
And the Honda CRX Tuner Series kit from Revell's '04 catalog:
And MPC's '78 Monte Carlo kit which was only released as a promo. Dean Milano had this one on eBay not long ago:
The IMC Dodge LVT-1000: