The example given was driving in rush hour traffic. I dont know about where you live, but around here thats under 20mph. Unlikely to kill anyone at that speed.
I used a plane with your whole family in it, because that's a closer comparison to the E350, and just as legal on a 3rd class medical. And again, I dont know where you fly, but where I fly I could take out a lot of people on the ground very easily with any aircraft. Southern CA doesn't have a lot of land without people on it.
You seem to think driving a car is really dangerous, but there are a hell of a lot of statistics on the books that show that you're wrong. The only reason so many people die in cars in comparison to planes is because there are exponentially more people driving them.
EDIT: to show my point, this census data shows 10.8 MILLION motor vehicle crashes in 2009, but only about 36,000 fatalities. That's a fatality only 0.3% of the time. I don't think that any of us needs to look at GA statistics to know cars are safer statistically speaking.
https://www.census.gov/compendia/statab/2012/tables/12s1103.pdf