3.5 year old back seat driver

Olivia now remarks at the speed limit signs on the side of the road while we go driving (clarification - I'm driving - she's in her seat). Because I drive a Civic with a digital speedometer, she also knows how fast I am going. So here's how the conversation goes:

Olivia: "Pa, that sign says one hundred."
Me (Pa): "That's right."
Olivia: "What does that mean?"
Me: "It means that's how fast we can go on this road."
Olivia: "But you're not doing one hundred..."
(I'm not - I'm doing 103)
Me: [rolling eyes]
Olivia: "You're going too fast Pa!"

She's 3 and a half....