Gomer

EMILY: Stop!

LORELAI: Gomer said!

Lorelai is referring to Gomer Pyle, a character from The Andy Griffith Show, played by Jim Nabors. Gomer was the slow-witted, naïve mechanic who worked at the local filling station; at first very ignorant about cars, his knowledge increased until he was quite competent.

Lorelai calls Richard “Gomer” because he’s dressed in overalls and doing a mechanic’s work on his car.