Khalid Mehdi, a Brooklyn man who drives for Uber and Lyft gets a lot of questions from riders. But perhaps the most frequently asked is in reference to his car. “They wonder, ‘Why is it always a Camry for a ride-share?’ ” says Mr. Mehdi, who drives a 2014 Toyota Camry LE.

I’ve often wondered myself. Every time I summon a car, the driver invariably pulls up in a black Camry—dangling pine-tree air freshener optional.

It...