The episode was inspired by George Russell Weller who in 2003 ran over and killed 10 people at a farmers market in Santa Monica, CA by driving through the crowd.
The retirement home, Shady Acres, is also the name of a fictional retirement community in Grand Theft Auto: Vice City (2002).
Grandpa Marsh says the government will never take away his "right to drive". However, in reality, operating a motor vehicle is rendered a privilege, not a right, as it requires a license.