(What kach22i said) I can't remember the thread where that car in #41 was discussed, having thought about it.
But... I got to thinking about what went down in 2013.
ecomodder.com: Project: ECOfamily Civic and its Aero Hitch Box / Boat Tail
The box is another subject but the Kamm-back had it's up and downs (oops punagain). The adventure is at
#202. Magnets. How do they [not] work?
I wanted to point to
#171 through #184. Here's the money shot:
Today I'd say spotwelds or Unispot studs instead of magnets. No holes, just spot paint if the hinges are removed.