""They decided to buy a used hearse ... ""
I'm not sure I find this all that weird. I went to school with a couple of guys who bought such a hearse. They left it basic black but installed one of the brightest red interiors I've ever seen. They installed massive speakers,amp and the then state of the art 8 track player.
The mortician that sold it to them refused to sell then a casket to complete the scene.