Aren't multi-story parkings a thing in Texas? They can massively increase the parking lot efficiency while costing relatively little (mostly steel and concrete for pillars and floors, almost zero walls).
Closeness to a highway could be beneficial for a factory, too.
Parking structures are very expensive to build. Concrete and steel are expensive and you need a lot of it to hold up the weight of all the vehicles (and the dynamic loads while they are driving around)
Closeness to a highway could be beneficial for a factory, too.