Has anyone thought of this?

[trevorbrady]

by Pillow

Most everything I can think of has been done before

That's where innovation is born! You're supposed to think harder or develop/evolve/adapt other ideas...

what about VW Polo headlamps or Lupo? Similar in size and shape to sloping beetle headlamps. Could be made to fit.
Toyota Corollas have a round-ish headlamp similar to the Subaru bug-eye one, both of which could be grafted into a bug front wing if there is enough room for the headlamp "bucket" in terms of wheel clearance.
Front aprons/spoilers from modern cars could be adapted to fit under a bug bumper.
REAR apron/air diffuser under the back bumper?
A rear windscreen that lifts up on gas lifters like a mid '90s Honda civic split tailgate?

I don't know how practicable these ideas are, but someone with the time might like to try!!