BAYTOWN, Texas -- As many as 500,000 vehicles may have been totaled by the flooding from Harvey, and that means rental cars are in high demand.

More than three-quarters of drivers have comprehensive insurance coverage, which would cover flood damage. However, the process to get a new vehicle can take months.

In the meantime, folks are finding it difficult to get a rental. Drive through the Houston area, and you'll see one car rental office after another with no vehicles available.

Enterprise Holdings, which owns Enterprise Rent-A-Car, National Car Rental and Alamo Rent A Car, already moved in more than 4,000 vehicles to the Houston area, and the plan is to add 17,000 more onto that in the next few weeks.

"Our network of U.S. car rental locations exceeds 6,400, so we are uniquely able to move vehicles from city to city and state to state as demand calls for it," said Lisa Martini, a spokesperson for the company.

Enterprise activated its Emergency Action Plan, which Martini said helps better coordinate the movement of vehicles to areas with critical needs. The company also has a Mobile Emergency Response Vehicle in Meyerland. That mobile branch office goes into hard hit areas during emergencies.

Betina Wolfowicz of Bellaire spent four days trying to find a rental car, longer than it took to find a contractor to repair her flooded first floor.

"I know they are overwhelmed," Wolfowicz told our partners at USA Today. "But it is frustrating."

Some other car rental companies also said they're moving in vehicles to the Houston area, but they were unable to provide specifics.