You betcha, KOHO can be used to rent cars! Though not all franchises will accept pre-paid cards. Each franchise may also be location dependent.
Just a heads up that for car rentals, hotels, and gas stations, merchants may put a pre-authorization hold (usually around 15-20%) on your card. This is by no means a charge, however, your funds will be held to ensure you have enough to cover the purchase (plus incidentals where applicable).
We can't release these holds ourselves. The correct amount will ‘settle’ within 16 days after the purchase.
Hot Tip: to get around this hassle, book your rental car using a different credit card and then pay the final amount using your KOHO card. Happy Travels 🚘