157 Four Car Auto Transport

General Information
The following information has been collected from original newspapers, catalogs, and magazines, some of which are freely available for reference below. The rest can be found in the site’s gallery. No aggregate catalogs (BrickLink, Brickset, etc.) were used.
Instructions: 5204
Advertised Part Count(s): 65 pieces
First Year Confirmed Available: 1970(USA)
The set makes its first and only appearance in the 1970 Sears catalog.
USA Only.
Most Likely Retirement Date: 1970(USA)
Last Year Seen Available: 1970
Aliases: Four Car Auto Transport, Auto Transport Set
Retail Price(s): $4.99(USA)
Rarity Score(Index): 5/7
Known Box/Packing Variants
There are two versions of the outer box, both of which seem to have been available at the same time. There was a plain box version, similar to boxes smaller Kraft sets used, then also the colorful box, seen below.
There are also two versions of the contents(which was not dependent on the outer box). Some will have four 1:87 LEGO vehicles of any variety, others will have four Minix cars as a substitute.
Box/Overview
The 157 Auto Transport doesn't have much recorded or definitive story to tell, though it seems to have been an easy way to eliminate inventory of LEGO 1:87 vehicles. While it isn't wholly unusual for these cars to be mixed with bricks, it is the first and last appearance with them alongside the mini-wheel system which was new for 1970(in North America at least).
As far as I've been able to tell, it was a Sears exclusive, with the colorful box being used in store and the plain box for catalog sales:


Contents
The set contained enough parts to build the model. 4x8 plates were waffle bottom, the LEGO print was only white, etc:
The set also contained four vehicles. If they were LEGO brand, they came in their clear garages. Below is an assembled example with Minix vehicles:
