Winter was the most fun time to drive a Beetle/Ghia! Once you got used to the rear engine handling (There's nothing better than a large empty icy parking lot!) you can "drift" it consistently and reliably, steering with the throttle. I used to enter my parents VeeDub in ice trials and beat Corvettes and Shelbys. Two-stroke SAABs, OTOH, were a tough nut to crack.
Your son's car needed a new muffler and heater muff. That was a "no compromise, no excuses" necessity in the north country in winter with those cars. "The Mono" took a lot of lives unecessarily.
I had a Karmann Ghia for a while. Fun car, but a little cramped for my size, and its body literally dissolved in our road salt. Oddly enough, despite its sexy appearance, it was out-performed by the beetle, which was 200 lbs lighter, and had a stiffer body, less susceptible to torsional distortion. Both were limited at the top end by engine RPM, negating the Ghia's aerodynamic advantage. My Ghia got a little light and squirrelly at top speed, not a confidence-inspiring feature at all.
Cheers,
Wes