The Delta Fin Buicks had front and rear doorhandles at different height just like that car, and the weird frontal treatment could be a hint to the 1951 GM LeSabre dreamcar which also had two centrally positioned headlights. Buick introduced the LeSabre nameplate for 1959, so maybe this was a styling proposal for the 1959 Buick LeSabre, taking the name and styling cues from the 1951 car.