You can mimic some of the SFE mods yourself.
Consider a partial grille block for the times of the year you can get away with it. Fixed, manual or automatic shutters depending on how far you want to get into it.
As has been suggested, I'd definitely focus (no pun intended
) on the aero mods, since overcoming aero drag is where most of your fuel is going.
Nice looking car - I've yet to ride in one yet.
Welcome to the forum - and thanks again for the support!