OK, after some Google Earth-ing, this might be it on the highway 99 just before the 152 to Los Banos:
google Earth coordinates:
It’s on Avenue 22 1/2 and CA 99.
It’s the only roadside building right off CA 99 going north on Google Earth that could be where I remember it being. From above it looks very much like it is the hamburger stand/hut with the dirt lot…
Any thoughts on this Jennifer_4 or twinwillow?