EMILY: It was that car, wasn’t it? The one her boyfriend made. Richard was dead set against letting her drive that death-mobile.
Richard’s concerns about the car now seem pretty valid. Not that a different car would have stopped Jess from swerving to hit a small animal, but a new car would have had airbags and modern safety features that might have stopped Rory from getting hurt at all in a minor accident. It’s also possible Rory would have been more wary of letting Jess drive a new car. And if Lorelai had forbidden Rory from having a car at all, then obviously there would have been no way for Jess to crash it.
Lorelai wouldn’t let her parents buy Rory a new car when she started attending Chilton, which now seems a bit unfair. She allowed Dean, her seventeen-year-old boyfriend, to build her a car instead, which was actually a much bigger gift from him than a new car from her grandparents, with way more strings attached. To an extent, Emily is justified in her anger, and correct that Lorelai, however unwittingly, helped bring the situation about by the choices she made.
Note that Emily calls a dangerous car a “death-mobile”, in a similar way to Lorelai’s description of a black limo as a “Luca Brasi-mobile“.