Really quick story, that's sorta kinda related........
As a teen in the mid-70s my uncle had a little early 60s T1 sedan, and although not racing anymore, he frequented the races a bit still. He ended up living with us for a few months, and we had a REALLY steep driveway, that little lowered Beetle always scraped the rear apron in and out.
Finally one day he got the craps up, just sat and looked at it. I suggested cutting the back part of the apron off, coz it stuck out so far, then it wouldn't scrape. So we did, no scraping, problem solved, YAY!!! All we did was trim out the rear apron almost up to the engine lid, and matched the curve of the engine lid to make it look good, then ended up later running a QP muffler in the centre of it. I ended up doing it to my last Beetle too, as a sort of flashback thing, I still like the look.
Fast forward about 3 or 4 years, and we both went to visit the races again, this time in my V8 coupe, and there were 3 Beetles there........and all three of them had the trimmed rear apron mod!
When we asked why, they said some sort of crap about letting the air out the back, reducing lift, HAHAHA!!!
It's funny how trends seem to catch on sometimes!
Make the car look the way YOU want it too.