From August 1955 this press photo shows the Hudson Contest Winners. They seem to be a rather well behaved group. It looks like it's a hot day and the Mickey planter looks pretty barren!
35 children accompanied by their parents participated in Hudson’s five-day all expense paid trip including two days at “Disneyland Park”.
From last July, here’s my post on the 1955 Hudson Magazine that features Walt Disney and Disneyland (link). I’ve got about 20 of these little magazines that cover the period of this contest yet there is no mention of the contest in any of the issues?