I think my car may have been previously owned by an electrician (J/K no offense to the electricians here)
I used to have a '78 Chevy malibu that I repaired all the heater/AC switch & blower motor connections with wire nuts. Also used wire nuts on the electric fuel pump wiring of my '88 T-Bird. None gave any issue at all.
As a former electrician, this amuses me greatly. In case anyone is wondering, yellow wire nuts (without the wings) and 1/2" conduit make a perfect pea shooter.
As a former electrician and used thousands of wire nuts I see no problem with using a good quality wire nut and correctly installed in certain locations. A note on using wire nuts for a pea shooter using an air compressor for wind power will really make them suckers fly