seat as manufactured and having an automobile seat contact plane 18 first stop or shoulder means 20 on a forward position of said base means platform means 24 having a foot support portion 26 and a pair of position adjusting leg portions 28 each having an adjustment slot 30 and second stop or shoulder means 29 adapted to be nested with said first stop or shoulder means 20 said foot support portion 26 being disposed at a generally right angle to said portions 28 and clamping means generally designated 32 for maintaining the position of said platform means relative to said plane 18 by forcing 20 and 29 into nesting contact once the height adjustment has been made the present structure 10 is designed with four segments and exemplary dimensions are given therefor the first segment is the base 14 preferably about twenty inches deep eighteen inches wide and one eighth of an inch thick this base may be an integral part of the restraining seat and formed for example as the floor of a conventional restraining seat during its manufacture the sides or lips 34 of the base should be approximately one inch high to rigidify the platform means 24 which is adapted to rest under the restraining seat and be maintained in position thereby when the restraining seat is strapped down to the auto seat 35 by the seat belt 36 these lips also function as a guard or basin for spilled food or liquid enlarged ends 38 of sides 34 provide structural support for first stop 20 to allow the adjustable platform structure 24 to be moved readily up and down and.