[MGB=MPG]

looks to me like you are pretty low already..

maybe some proper shaped fairs [wings] on the side formed of fiberglas and fitted ..that fair fitted does not seem right to me either, ,, the track dog splitter is made of fiberglas and fits on top of it i think .

if i were to use grill blocking i would want louvers so i could get engine cooling air in there when i needed it .

IDK what your wheels are like but here they show data 4.5 % gain for smooth full wheel covers .. Pizza Pans .. having a little cash i went with Chrome Moons

edit: those wheels look aero to me , i dinna think you'd show 4.5, pizza pans would be unasthetic and moon wouldna fit