The requirement for a car was used to subsidize company operations.
"Can you pick up the cake for Joe's retirement during lunch?"
"Please pick up the mail on your way into work & get me a pack of cigarettes too."
"Drop off the samples at the printers on your way home"
It's coercive & a cost/mile reimbursement never covers the full cost of owning a vehicle.
It offloads corporate expenses onto employees & it's used for unpaid overtime running errands.